diff --git a/RegExpSupport/gen/org/intellij/lang/regexp/_RegExLexer.java b/RegExpSupport/gen/org/intellij/lang/regexp/_RegExLexer.java
index 24fa1e4c2829..9040c9d8e677 100644
--- a/RegExpSupport/gen/org/intellij/lang/regexp/_RegExLexer.java
+++ b/RegExpSupport/gen/org/intellij/lang/regexp/_RegExLexer.java
@@ -191,19 +191,19 @@ class _RegExLexer implements FlexLexer {
     "\1\17\1\20\1\21\1\22\1\2\1\23\1\24\1\25"+
     "\1\26\1\27\1\30\1\31\1\30\1\32\1\33\1\34"+
     "\1\10\1\35\1\2\1\36\1\37\1\23\1\40\1\41"+
-    "\1\42\1\43\1\44\1\45\1\1\1\46\1\47\2\50"+
-    "\1\51\1\52\1\0\1\53\1\54\1\55\1\56\1\57"+
-    "\1\60\1\10\1\61\1\62\1\63\1\64\1\10\1\64"+
-    "\1\65\2\66\1\67\1\70\1\71\1\72\1\73\1\74"+
-    "\1\75\1\10\1\76\1\77\1\100\1\0\1\101\1\102"+
-    "\1\103\1\104\1\0\1\105\1\106\1\107\1\110\1\111"+
-    "\1\0\1\112\1\0\1\113\1\0\1\114\1\115\1\116"+
-    "\2\72\1\117\1\120\1\121\1\122\1\123\1\124\1\125"+
-    "\1\126\1\0\1\113\1\0\1\127\2\72\1\117\1\130"+
-    "\1\113\1\72\1\117\1\72\1\131\4\72";
+    "\1\42\1\43\1\44\1\45\1\1\1\26\1\46\1\47"+
+    "\2\50\1\51\1\52\1\0\1\53\1\54\1\55\1\56"+
+    "\1\57\1\60\1\10\1\61\1\62\1\63\1\64\1\10"+
+    "\1\64\1\65\2\66\1\67\1\70\1\71\1\72\1\73"+
+    "\1\74\1\75\1\10\1\76\1\77\1\100\1\0\1\101"+
+    "\1\102\1\103\1\104\1\0\1\105\1\106\1\107\1\110"+
+    "\1\111\1\0\1\112\1\0\1\113\1\0\1\114\1\115"+
+    "\1\116\2\72\1\117\1\120\1\121\1\122\1\123\1\124"+
+    "\1\125\1\126\1\0\1\113\1\0\1\127\2\72\1\117"+
+    "\1\130\1\113\1\72\1\117\1\72\1\131\4\72";
 
   private static int [] zzUnpackAction() {
-    int [] result = new int[138];
+    int [] result = new int[139];
     int offset = 0;
     offset = zzUnpackAction(ZZ_ACTION_PACKED_0, offset, result);
     return result;
@@ -235,20 +235,20 @@ class _RegExLexer implements FlexLexer {
     "\0\u03e0\0\u04d8\0\u03e0\0\u0516\0\u03e0\0\u0554\0\u03e0\0\u03e0"+
     "\0\u03e0\0\u0592\0\u03e0\0\u05d0\0\u03e0\0\u060e\0\u03e0\0\u064c"+
     "\0\u03e0\0\u03e0\0\u045c\0\u03e0\0\u03e0\0\u03e0\0\u068a\0\u06c8"+
-    "\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u0706\0\u0744\0\u03e0"+
-    "\0\u0782\0\u07c0\0\u03e0\0\u07fe\0\u083c\0\u03e0\0\u03e0\0\u03e0"+
-    "\0\u03e0\0\u03e0\0\u03e0\0\u087a\0\u08b8\0\u03e0\0\u03e0\0\u08f6"+
-    "\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u0934\0\u0972\0\u03e0\0\u03e0"+
-    "\0\u09b0\0\u03e0\0\u03e0\0\u03e0\0\u09ee\0\u03e0\0\u03e0\0\u03e0"+
-    "\0\u03e0\0\u0a2c\0\u0a6a\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u0aa8"+
-    "\0\u03e0\0\u0ae6\0\u0b24\0\u0b62\0\u03e0\0\u03e0\0\u03e0\0\u0ba0"+
-    "\0\u0bde\0\u0c1c\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u03e0"+
-    "\0\u03e0\0\u0c5a\0\u0c98\0\u0cd6\0\u03e0\0\u0d14\0\u03e0\0\u0d52"+
-    "\0\u03e0\0\u03e0\0\u0d90\0\u0dce\0\u0e0c\0\u03e0\0\u0e4a\0\u0e88"+
-    "\0\u0ec6\0\u0f04";
+    "\0\u03e0\0\u03e0\0\u0706\0\u03e0\0\u03e0\0\u03e0\0\u0744\0\u0782"+
+    "\0\u03e0\0\u07c0\0\u07fe\0\u03e0\0\u083c\0\u087a\0\u03e0\0\u03e0"+
+    "\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u08b8\0\u08f6\0\u03e0\0\u03e0"+
+    "\0\u0934\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u0972\0\u09b0\0\u03e0"+
+    "\0\u03e0\0\u09ee\0\u03e0\0\u03e0\0\u03e0\0\u0a2c\0\u03e0\0\u03e0"+
+    "\0\u03e0\0\u03e0\0\u0a6a\0\u0aa8\0\u03e0\0\u03e0\0\u03e0\0\u03e0"+
+    "\0\u0ae6\0\u03e0\0\u0b24\0\u0b62\0\u0ba0\0\u03e0\0\u03e0\0\u03e0"+
+    "\0\u0bde\0\u0c1c\0\u0c5a\0\u03e0\0\u03e0\0\u03e0\0\u03e0\0\u03e0"+
+    "\0\u03e0\0\u03e0\0\u0c98\0\u0cd6\0\u0d14\0\u03e0\0\u0d52\0\u03e0"+
+    "\0\u0d90\0\u03e0\0\u03e0\0\u0dce\0\u0e0c\0\u0e4a\0\u03e0\0\u0e88"+
+    "\0\u0ec6\0\u0f04\0\u0f42";
 
   private static int [] zzUnpackRowMap() {
-    int [] result = new int[138];
+    int [] result = new int[139];
     int offset = 0;
     offset = zzUnpackRowMap(ZZ_ROWMAP_PACKED_0, offset, result);
     return result;
@@ -287,66 +287,67 @@ class _RegExLexer implements FlexLexer {
     "\1\64\7\43\1\64\4\43\1\64\20\43\1\62\1\43"+
     "\1\63\1\43\1\27\63\43\5\65\1\66\5\65\1\67"+
     "\1\65\1\70\10\65\26\67\1\65\3\67\3\65\1\67"+
-    "\4\65\1\71\5\65\65\13\1\72\10\13\13\65\1\46"+
-    "\12\65\26\46\1\65\3\46\3\65\1\46\6\65\1\73"+
-    "\16\65\1\46\12\65\26\46\1\65\3\46\1\65\1\74"+
-    "\1\65\1\46\17\65\1\66\5\65\1\46\12\65\26\46"+
-    "\1\65\3\46\3\65\1\46\13\65\2\44\2\65\1\66"+
-    "\5\65\1\46\3\65\1\44\6\65\26\46\1\44\3\46"+
-    "\3\65\1\46\12\65\13\75\1\46\4\75\1\32\5\75"+
-    "\26\46\1\75\3\46\3\75\1\46\4\75\1\76\5\75"+
-    "\120\0\1\77\64\0\1\100\1\101\5\0\1\102\55\0"+
-    "\1\103\1\104\1\105\4\106\1\103\1\107\1\103\1\107"+
-    "\1\110\1\103\1\111\1\112\1\103\1\107\5\106\2\113"+
-    "\1\114\1\115\3\116\3\117\1\120\2\121\2\122\3\123"+
-    "\1\110\1\124\1\125\1\126\1\104\1\127\1\130\1\131"+
-    "\2\103\1\112\1\110\1\103\1\112\1\103\1\112\6\103"+
-    "\47\0\1\132\27\0\2\44\14\0\1\44\34\0\1\44"+
+    "\4\65\1\71\5\65\65\13\1\72\10\13\13\65\1\73"+
+    "\12\65\26\73\1\65\3\73\3\65\1\73\6\65\1\74"+
+    "\16\65\1\73\12\65\26\73\1\65\3\73\1\65\1\75"+
+    "\1\65\1\73\17\65\1\66\5\65\1\73\12\65\26\73"+
+    "\1\65\3\73\3\65\1\73\13\65\2\44\2\65\1\66"+
+    "\5\65\1\73\3\65\1\44\6\65\26\73\1\44\3\73"+
+    "\3\65\1\73\12\65\13\76\1\46\4\76\1\32\5\76"+
+    "\26\46\1\76\3\46\3\76\1\46\4\76\1\77\5\76"+
+    "\120\0\1\100\64\0\1\101\1\102\5\0\1\103\55\0"+
+    "\1\104\1\105\1\106\4\107\1\104\1\110\1\104\1\110"+
+    "\1\111\1\104\1\112\1\113\1\104\1\110\5\107\2\114"+
+    "\1\115\1\116\3\117\3\120\1\121\2\122\2\123\3\124"+
+    "\1\111\1\125\1\126\1\127\1\105\1\130\1\131\1\132"+
+    "\2\104\1\113\1\111\1\104\1\113\1\104\1\113\6\104"+
+    "\47\0\1\133\27\0\2\44\14\0\1\44\34\0\1\44"+
     "\22\0\2\46\1\0\2\46\5\0\5\46\6\0\32\46"+
-    "\3\0\1\46\23\0\1\133\75\0\1\134\1\135\5\0"+
-    "\1\102\47\0\1\136\5\0\1\103\1\104\1\105\4\106"+
-    "\1\103\3\107\1\110\1\103\1\111\1\112\1\103\1\107"+
-    "\5\106\2\113\1\114\1\115\3\116\3\117\1\120\2\121"+
-    "\2\122\3\123\1\110\1\124\1\125\1\126\1\104\1\127"+
-    "\1\130\1\131\2\103\1\112\1\110\1\103\1\112\1\103"+
-    "\1\112\6\103\71\0\1\137\17\0\1\67\12\0\26\67"+
+    "\3\0\1\46\23\0\1\134\75\0\1\135\1\136\5\0"+
+    "\1\103\47\0\1\137\5\0\1\104\1\105\1\106\4\107"+
+    "\1\104\3\110\1\111\1\104\1\112\1\113\1\104\1\110"+
+    "\5\107\2\114\1\115\1\116\3\117\3\120\1\121\2\122"+
+    "\2\123\3\124\1\111\1\125\1\126\1\127\1\105\1\130"+
+    "\1\131\1\132\2\104\1\113\1\111\1\104\1\113\1\104"+
+    "\1\113\6\104\71\0\1\140\17\0\1\67\12\0\26\67"+
     "\1\0\3\67\3\0\1\67\25\0\1\70\12\0\26\70"+
-    "\1\0\3\70\3\0\1\70\23\0\1\140\70\0\1\141"+
-    "\37\0\1\142\13\0\1\143\1\144\6\0\1\145\1\0"+
-    "\1\145\1\146\1\147\1\150\11\0\1\100\75\0\1\151"+
-    "\1\152\64\0\2\104\51\0\1\104\23\0\1\153\51\0"+
-    "\1\153\27\0\1\154\147\0\1\155\1\156\14\0\76\157"+
-    "\1\0\2\160\3\0\1\161\20\0\2\160\1\0\1\160"+
-    "\4\0\3\160\5\0\2\160\3\0\1\160\22\0\2\162"+
-    "\24\0\2\162\1\0\1\162\4\0\3\162\5\0\2\162"+
-    "\3\0\1\162\101\0\1\163\1\164\25\0\1\165\144\0"+
-    "\1\166\12\0\1\167\75\0\1\170\1\171\1\0\5\172"+
-    "\1\0\70\172\11\0\1\151\66\0\1\173\51\0\1\173"+
-    "\52\0\1\174\45\0\2\175\24\0\2\175\1\0\1\175"+
-    "\4\0\3\175\5\0\2\175\3\0\1\175\22\0\2\176"+
-    "\4\0\1\177\17\0\2\176\1\0\1\176\4\0\3\176"+
-    "\5\0\2\176\3\0\1\176\22\0\2\200\24\0\2\200"+
-    "\1\0\1\200\4\0\3\200\5\0\2\200\3\0\1\200"+
-    "\21\0\5\172\1\201\70\172\2\0\1\202\51\0\1\202"+
-    "\30\0\1\116\67\0\2\203\4\0\1\175\17\0\2\203"+
-    "\1\0\1\203\4\0\3\203\5\0\2\203\3\0\1\203"+
-    "\22\0\2\204\24\0\2\204\1\0\1\204\4\0\3\204"+
-    "\5\0\2\204\3\0\1\204\22\0\2\205\4\0\1\175"+
-    "\17\0\2\205\1\0\1\205\4\0\3\205\5\0\2\205"+
-    "\3\0\1\205\22\0\2\206\24\0\2\206\1\0\1\206"+
-    "\4\0\3\206\5\0\2\206\3\0\1\206\22\0\2\207"+
-    "\4\0\1\175\17\0\2\207\1\0\1\207\4\0\3\207"+
-    "\5\0\2\207\3\0\1\207\22\0\2\210\4\0\1\175"+
-    "\17\0\2\210\1\0\1\210\4\0\3\210\5\0\2\210"+
-    "\3\0\1\210\22\0\2\211\4\0\1\175\17\0\2\211"+
-    "\1\0\1\211\4\0\3\211\5\0\2\211\3\0\1\211"+
-    "\22\0\2\212\4\0\1\175\17\0\2\212\1\0\1\212"+
-    "\4\0\3\212\5\0\2\212\3\0\1\212\22\0\2\212"+
-    "\4\0\1\177\17\0\2\212\1\0\1\212\4\0\3\212"+
-    "\5\0\2\212\3\0\1\212\21\0";
+    "\1\0\3\70\3\0\1\70\13\0\2\73\10\0\5\73"+
+    "\6\0\32\73\3\0\1\73\23\0\1\141\70\0\1\142"+
+    "\37\0\1\143\13\0\1\144\1\145\6\0\1\146\1\0"+
+    "\1\146\1\147\1\150\1\151\11\0\1\101\75\0\1\152"+
+    "\1\153\64\0\2\105\51\0\1\105\23\0\1\154\51\0"+
+    "\1\154\27\0\1\155\147\0\1\156\1\157\14\0\76\160"+
+    "\1\0\2\161\3\0\1\162\20\0\2\161\1\0\1\161"+
+    "\4\0\3\161\5\0\2\161\3\0\1\161\22\0\2\163"+
+    "\24\0\2\163\1\0\1\163\4\0\3\163\5\0\2\163"+
+    "\3\0\1\163\101\0\1\164\1\165\25\0\1\166\144\0"+
+    "\1\167\12\0\1\170\75\0\1\171\1\172\1\0\5\173"+
+    "\1\0\70\173\11\0\1\152\66\0\1\174\51\0\1\174"+
+    "\52\0\1\175\45\0\2\176\24\0\2\176\1\0\1\176"+
+    "\4\0\3\176\5\0\2\176\3\0\1\176\22\0\2\177"+
+    "\4\0\1\200\17\0\2\177\1\0\1\177\4\0\3\177"+
+    "\5\0\2\177\3\0\1\177\22\0\2\201\24\0\2\201"+
+    "\1\0\1\201\4\0\3\201\5\0\2\201\3\0\1\201"+
+    "\21\0\5\173\1\202\70\173\2\0\1\203\51\0\1\203"+
+    "\30\0\1\117\67\0\2\204\4\0\1\176\17\0\2\204"+
+    "\1\0\1\204\4\0\3\204\5\0\2\204\3\0\1\204"+
+    "\22\0\2\205\24\0\2\205\1\0\1\205\4\0\3\205"+
+    "\5\0\2\205\3\0\1\205\22\0\2\206\4\0\1\176"+
+    "\17\0\2\206\1\0\1\206\4\0\3\206\5\0\2\206"+
+    "\3\0\1\206\22\0\2\207\24\0\2\207\1\0\1\207"+
+    "\4\0\3\207\5\0\2\207\3\0\1\207\22\0\2\210"+
+    "\4\0\1\176\17\0\2\210\1\0\1\210\4\0\3\210"+
+    "\5\0\2\210\3\0\1\210\22\0\2\211\4\0\1\176"+
+    "\17\0\2\211\1\0\1\211\4\0\3\211\5\0\2\211"+
+    "\3\0\1\211\22\0\2\212\4\0\1\176\17\0\2\212"+
+    "\1\0\1\212\4\0\3\212\5\0\2\212\3\0\1\212"+
+    "\22\0\2\213\4\0\1\176\17\0\2\213\1\0\1\213"+
+    "\4\0\3\213\5\0\2\213\3\0\1\213\22\0\2\213"+
+    "\4\0\1\200\17\0\2\213\1\0\1\213\4\0\3\213"+
+    "\5\0\2\213\3\0\1\213\21\0";
 
   private static int [] zzUnpackTrans() {
-    int [] result = new int[3906];
+    int [] result = new int[3968];
     int offset = 0;
     offset = zzUnpackTrans(ZZ_TRANS_PACKED_0, offset, result);
     return result;
@@ -387,15 +388,15 @@ class _RegExLexer implements FlexLexer {
     "\12\0\1\1\5\0\2\11\1\1\2\11\2\1\12\11"+
     "\1\1\1\11\1\1\1\11\1\1\3\11\1\1\1\11"+
     "\1\1\1\11\1\1\1\11\1\1\2\11\1\1\3\11"+
-    "\2\1\5\11\2\1\1\11\1\0\1\1\1\11\2\1"+
-    "\6\11\2\1\2\11\1\1\4\11\2\1\2\11\1\1"+
-    "\3\11\1\0\4\11\1\0\1\1\4\11\1\0\1\11"+
-    "\1\0\1\1\1\0\3\11\3\1\7\11\1\0\1\1"+
-    "\1\0\1\11\1\1\1\11\1\1\2\11\3\1\1\11"+
-    "\4\1";
+    "\2\1\2\11\1\1\3\11\2\1\1\11\1\0\1\1"+
+    "\1\11\2\1\6\11\2\1\2\11\1\1\4\11\2\1"+
+    "\2\11\1\1\3\11\1\0\4\11\1\0\1\1\4\11"+
+    "\1\0\1\11\1\0\1\1\1\0\3\11\3\1\7\11"+
+    "\1\0\1\1\1\0\1\11\1\1\1\11\1\1\2\11"+
+    "\3\1\1\11\4\1";
 
   private static int [] zzUnpackAttribute() {
-    int [] result = new int[138];
+    int [] result = new int[139];
     int offset = 0;
     offset = zzUnpackAttribute(ZZ_ATTRIBUTE_PACKED_0, offset, result);
     return result;
diff --git a/RegExpSupport/src/org/intellij/lang/regexp/RegExpParser.java b/RegExpSupport/src/org/intellij/lang/regexp/RegExpParser.java
index 06a6d3f3c77e..9c16d5334237 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/RegExpParser.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/RegExpParser.java
@@ -217,7 +217,8 @@ public class RegExpParser implements PsiParser {
 
     // DEFLIST
     if (parseClassIntersection(builder)) {
-      while (RegExpTT.CHARACTERS2.contains(builder.getTokenType()) ||
+      while (RegExpTT.CHARACTERS.contains(builder.getTokenType()) ||
+             builder.getTokenType() == RegExpTT.CHAR_CLASS ||
              builder.getTokenType() == RegExpTT.CLASS_BEGIN ||
              builder.getTokenType() == RegExpTT.PROPERTY ||
              builder.getTokenType() == RegExpTT.BRACKET_EXPRESSION_BEGIN) {
@@ -257,9 +258,14 @@ public class RegExpParser implements PsiParser {
       else if (token == RegExpTT.BRACKET_EXPRESSION_BEGIN) {
         parseBracketExpression(builder);
       }
-      else if (RegExpTT.CHARACTERS2.contains(token)) {
+      else if (RegExpTT.CHARACTERS.contains(token)) {
         parseSimpleClassdef(builder);
       }
+      else if (token == RegExpTT.CHAR_CLASS) {
+        final PsiBuilder.Marker m = builder.mark();
+        builder.advanceLexer();
+        m.done(RegExpElementTypes.SIMPLE_CLASS);
+      }
       else if (token == RegExpTT.PROPERTY) {
         parseProperty(builder);
       }
@@ -291,7 +297,7 @@ public class RegExpParser implements PsiParser {
   }
 
   private void parseSimpleClassdef(PsiBuilder builder) {
-    assert RegExpTT.CHARACTERS2.contains(builder.getTokenType());
+    assert RegExpTT.CHARACTERS.contains(builder.getTokenType());
 
     final PsiBuilder.Marker marker = builder.mark();
     makeChar(builder);
@@ -301,7 +307,7 @@ public class RegExpParser implements PsiParser {
       builder.advanceLexer();
 
       final IElementType t = builder.getTokenType();
-      if (RegExpTT.CHARACTERS2.contains(t)) {
+      if (RegExpTT.CHARACTERS.contains(t) || t == RegExpTT.CHAR_CLASS) {
         m.drop();
         makeChar(builder);
         marker.done(RegExpElementTypes.CHAR_RANGE);
@@ -449,7 +455,7 @@ public class RegExpParser implements PsiParser {
       marker.drop();
       parseNamedCharacter(builder);
     }
-    else if (RegExpTT.SIMPLE_CLASSES.contains(type)) {
+    else if (type == RegExpTT.DOT || type == RegExpTT.CHAR_CLASS) {
       builder.advanceLexer();
       marker.done(RegExpElementTypes.SIMPLE_CLASS);
     }
diff --git a/RegExpSupport/src/org/intellij/lang/regexp/RegExpTT.java b/RegExpSupport/src/org/intellij/lang/regexp/RegExpTT.java
index 6ad066f37b5d..2da30a8be0da 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/RegExpTT.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/RegExpTT.java
@@ -135,22 +135,17 @@ public interface RegExpTT {
     IElementType RUBY_QUOTED_NAMED_GROUP_CALL = new RegExpElementType("RUBY_QUOTED_NAMED_GROUP_CALL");
 
     TokenSet CHARACTERS = TokenSet.create(CHARACTER,
-            ESC_CTRL_CHARACTER,
-            ESC_CHARACTER,
-            CTRL_CHARACTER,
-            CTRL,
-            UNICODE_CHAR,
-            HEX_CHAR, BAD_HEX_VALUE,
-            OCT_CHAR, BAD_OCT_VALUE,
-            REDUNDANT_ESCAPE,
-            MINUS,
-            StringEscapesTokenTypes.INVALID_UNICODE_ESCAPE_TOKEN,
-            StringEscapesTokenTypes.INVALID_CHARACTER_ESCAPE_TOKEN);
-
-    TokenSet SIMPLE_CLASSES = TokenSet.create(DOT, CHAR_CLASS);
-
-    // caret is just a character in classes after the first position: [a^] matches "a" or "^"
-    TokenSet CHARACTERS2 = TokenSet.orSet(CHARACTERS, SIMPLE_CLASSES);
+                                          ESC_CTRL_CHARACTER,
+                                          ESC_CHARACTER,
+                                          CTRL_CHARACTER,
+                                          CTRL,
+                                          UNICODE_CHAR,
+                                          HEX_CHAR, BAD_HEX_VALUE,
+                                          OCT_CHAR, BAD_OCT_VALUE,
+                                          REDUNDANT_ESCAPE,
+                                          MINUS,
+                                          StringEscapesTokenTypes.INVALID_UNICODE_ESCAPE_TOKEN,
+                                          StringEscapesTokenTypes.INVALID_CHARACTER_ESCAPE_TOKEN);
 
     TokenSet QUANTIFIERS = TokenSet.create(QUEST, PLUS, STAR, LBRACE);
 
diff --git a/RegExpSupport/src/org/intellij/lang/regexp/regexp-lexer.flex b/RegExpSupport/src/org/intellij/lang/regexp/regexp-lexer.flex
index 16ff07395dab..d90f4964e2b2 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/regexp-lexer.flex
+++ b/RegExpSupport/src/org/intellij/lang/regexp/regexp-lexer.flex
@@ -100,6 +100,7 @@ RBRACKET="]"
 
 ESCAPE="\\"
 NAME=[:letter:]([:letter:]|_|-|" "|"("|")"|[:digit:])*
+GROUP_NAME=[:letter:]([:letter:]|_|-|" "|[:digit:])*
 ANY=[^]
 
 META1 = {ESCAPE} | {LBRACKET} | "^"
@@ -340,25 +341,25 @@ HEX_CHAR=[0-9a-fA-F]
 }
 
 <NAMED_GROUP> {
-  {NAME}            { return RegExpTT.NAME; }
+  {GROUP_NAME}      { return RegExpTT.NAME; }
   ">"               { yybegin(YYINITIAL); return RegExpTT.GT; }
   {ANY}             { yybegin(YYINITIAL); return RegExpTT.BAD_CHARACTER; }
 }
 
 <QUOTED_NAMED_GROUP> {
-  {NAME}            { return RegExpTT.NAME; }
+  {GROUP_NAME}      { return RegExpTT.NAME; }
   "'"               { yybegin(YYINITIAL); return RegExpTT.QUOTE; }
   {ANY}             { yybegin(YYINITIAL); return RegExpTT.BAD_CHARACTER; }
 }
 
 <PY_NAMED_GROUP_REF> {
-  {NAME}            { return RegExpTT.NAME;   }
+  {GROUP_NAME}      { return RegExpTT.NAME;   }
   ")"               { yybegin(YYINITIAL); return RegExpTT.GROUP_END; }
   {ANY}             { yybegin(YYINITIAL); return RegExpTT.BAD_CHARACTER; }
 }
 
 <PY_COND_REF> {
-  {NAME}            { return RegExpTT.NAME; }
+  {GROUP_NAME}      { return RegExpTT.NAME; }
   [:digit:]+        { return RegExpTT.NUMBER; }
   ")"               { yybegin(YYINITIAL); return RegExpTT.GROUP_END; }
   {ANY}             { yybegin(YYINITIAL); return RegExpTT.BAD_CHARACTER; }
diff --git a/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java b/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
index 3618b81df854..ee1a4ad01fda 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
@@ -84,9 +84,7 @@ public final class RegExpAnnotator extends RegExpElementVisitor implements Annot
   public void visitRegExpCharRange(RegExpCharRange range) {
     final RegExpCharRange.Endpoint from = range.getFrom();
     final RegExpCharRange.Endpoint to = range.getTo();
-    final boolean a = from instanceof RegExpChar;
-    final boolean b = to instanceof RegExpChar;
-    if (a && b) {
+    if (from instanceof RegExpChar && to instanceof RegExpChar) {
       final Character t = ((RegExpChar)to).getValue();
       final Character f = ((RegExpChar)from).getValue();
       if (t != null && f != null) {
@@ -99,8 +97,8 @@ public final class RegExpAnnotator extends RegExpElementVisitor implements Annot
         }
       }
     }
-    else if (a != b) {
-      myHolder.createErrorAnnotation(range, "Character class (e.g. '\\\\w') may not be used inside character range");
+    else if (to instanceof RegExpSimpleClass) {
+      myHolder.createErrorAnnotation(to, "Character class not allowed inside character range");
     }
     else if (from.getText().equals(to.getText())) {
       myHolder.createWarningAnnotation(range, "Redundant character range");
@@ -151,12 +149,20 @@ public final class RegExpAnnotator extends RegExpElementVisitor implements Annot
     }
   }
 
-  private void checkForDuplicates(RegExpClassElement element, Set<Character> seen) {
+  private void checkForDuplicates(RegExpClassElement element, Set<Object> seen) {
     if (element instanceof RegExpChar) {
       final RegExpChar regExpChar = (RegExpChar)element;
       final Character value = regExpChar.getValue();
       if (value != null && !seen.add(value)) {
-        myHolder.createWarningAnnotation(regExpChar, "Duplicate character '" + regExpChar.getText() + "' in character class");
+        myHolder.createWarningAnnotation(regExpChar, "Duplicate character '" + regExpChar.getText() + "' inside character class");
+      }
+    }
+    else if (element instanceof RegExpSimpleClass) {
+      final RegExpSimpleClass regExpSimpleClass = (RegExpSimpleClass)element;
+      final RegExpSimpleClass.Kind kind = regExpSimpleClass.getKind();
+      if (!seen.add(kind)) {
+        myHolder.createWarningAnnotation(regExpSimpleClass, "Duplicate predefined character class '" + regExpSimpleClass.getText() +
+                                                            "' inside character class");
       }
     }
     else if (element instanceof RegExpClass) {
diff --git a/RegExpSupport/test/org/intellij/lang/regexp/RegExpParsingTest.java b/RegExpSupport/test/org/intellij/lang/regexp/RegExpParsingTest.java
index f351c303a042..1d057c835fd0 100644
--- a/RegExpSupport/test/org/intellij/lang/regexp/RegExpParsingTest.java
+++ b/RegExpSupport/test/org/intellij/lang/regexp/RegExpParsingTest.java
@@ -184,6 +184,10 @@ public class RegExpParsingTest extends ParsingTestCase {
   public void testGroups33() throws IOException { doCodeTest("(?<asdf>[a-c])\\1"); }
   public void testGroups34() throws IOException { doCodeTest("(?<asdf>[a-c])\\k<asdf>"); }
   public void testGroups35() throws IOException { doCodeTest("\\k<adsf>"); }
+  public void testGroups36() throws IOException { doCodeTest("(?P<name>{"); }
+  public void testGroups37() throws IOException { doCodeTest("(?P=name)"); }
+  public void testGroups38() throws IOException { doCodeTest("\\g'name'"); }
+  public void testGroups39() throws IOException { doCodeTest("(?(name)yes-pattern|no-pattern)"); }
 
   public void testEscapes1() throws IOException { doCodeTest("\\q"); }
   public void testEscapes2() throws IOException { doCodeTest("\\#"); }
diff --git a/RegExpSupport/testData/RETest.xml b/RegExpSupport/testData/RETest.xml
index 75ca74a4696f..8069ee6fd0f8 100644
--- a/RegExpSupport/testData/RETest.xml
+++ b/RegExpSupport/testData/RETest.xml
@@ -37,7 +37,11 @@
   </quantifiers>
   <charclasses>
     <test verify="false">
-      <pattern><![CDATA[[<warning descr="Redundant character range">\w-\w</warning>]]]></pattern>
+      <pattern><![CDATA[[\w-<warning descr="Duplicate predefined character class '\w' inside character class">\w</warning>]]]></pattern>
+      <expected>OK</expected>
+    </test>
+    <test>
+      <pattern>[\w-a]</pattern>
       <expected>OK</expected>
     </test>
     <test host="com.intellij.psi.impl.JavaRegExpHost">
@@ -106,7 +110,7 @@
       <expected>OK</expected>
     </test>
     <test>
-      <pattern><![CDATA[[\Qabc?*+.)<warning descr="Duplicate character ')' in character class">)</warning>]<warning descr="Duplicate character ']' in character class">]</warning>[<warning descr="Duplicate character ']' in character class">]</warning>\E]]]></pattern>
+      <pattern><![CDATA[[\Qabc?*+.)<warning descr="Duplicate character ')' inside character class">)</warning>]<warning descr="Duplicate character ']' inside character class">]</warning>[<warning descr="Duplicate character ']' inside character class">]</warning>\E]]]></pattern>
       <expected>OK</expected>
     </test>
     <test host="com.intellij.psi.impl.JavaRegExpHost">
@@ -133,7 +137,7 @@
       <expected>OK</expected>
     </test>
     <test>
-      <pattern><![CDATA[[:xdig<warning descr="Duplicate character 'i' in character class">i</warning>t<warning descr="Duplicate character ':' in character class">:</warning>]+]]></pattern>
+      <pattern><![CDATA[[:xdig<warning descr="Duplicate character 'i' inside character class">i</warning>t<warning descr="Duplicate character ':' inside character class">:</warning>]+]]></pattern>
       <expected>OK</expected>
     </test>
   </namedchars>
diff --git a/RegExpSupport/testData/psi/Charclasses61.txt b/RegExpSupport/testData/psi/Charclasses61.txt
index 01e2ae8f4b48..13bfb2cb45dc 100644
--- a/RegExpSupport/testData/psi/Charclasses61.txt
+++ b/RegExpSupport/testData/psi/Charclasses61.txt
@@ -3,10 +3,11 @@ REGEXP_FILE
     RegExpBranchImpl: <[\w-\w]>
       RegExpClassImpl: <[\w-\w]>
         PsiElement(CLASS_BEGIN)('[')
-        RegExpCharRangeImpl: <\w-\w>
+        RegExpUnionImpl: <\w-\w>
           RegExpSimpleClassImpl: <\w>
             PsiElement(CHAR_CLASS)('\w')
-          PsiElement(MINUS)('-')
+          RegExpCharImpl: <->
+            PsiElement(MINUS)('-')
           RegExpSimpleClassImpl: <\w>
             PsiElement(CHAR_CLASS)('\w')
         PsiElement(CLASS_END)(']')
\ No newline at end of file
diff --git a/RegExpSupport/testData/psi/Groups36.txt b/RegExpSupport/testData/psi/Groups36.txt
new file mode 100644
index 000000000000..bb6cfb567a65
--- /dev/null
+++ b/RegExpSupport/testData/psi/Groups36.txt
@@ -0,0 +1,14 @@
+REGEXP_FILE
+  RegExpPatternImpl: <(?P<name>{>
+    RegExpBranchImpl: <(?P<name>{>
+      RegExpClosureImpl: <(?P<name>{>
+        RegExpGroupImpl: <(?P<name>>
+          PsiElement(PYTHON_NAMED_GROUP)('(?P<')
+          PsiElement(NAME)('name')
+          PsiElement(GT)('>')
+          PsiErrorElement:Dangling metacharacter
+            <empty list>
+        RegExpQuantifierImpl: <{>
+          PsiElement(LBRACE)('{')
+          PsiErrorElement:Number expected
+            <empty list>
\ No newline at end of file
diff --git a/RegExpSupport/testData/psi/Groups37.txt b/RegExpSupport/testData/psi/Groups37.txt
new file mode 100644
index 000000000000..7944e6527490
--- /dev/null
+++ b/RegExpSupport/testData/psi/Groups37.txt
@@ -0,0 +1,7 @@
+REGEXP_FILE
+  RegExpPatternImpl: <(?P=name)>
+    RegExpBranchImpl: <(?P=name)>
+      RegExpNamedGroupRefImpl: <(?P=name)>
+        PsiElement(PYTHON_NAMED_GROUP_REF)('(?P=')
+        PsiElement(NAME)('name')
+        PsiElement(GROUP_END)(')')
\ No newline at end of file
diff --git a/RegExpSupport/testData/psi/Groups38.txt b/RegExpSupport/testData/psi/Groups38.txt
new file mode 100644
index 000000000000..5603f065cdd4
--- /dev/null
+++ b/RegExpSupport/testData/psi/Groups38.txt
@@ -0,0 +1,7 @@
+REGEXP_FILE
+  RegExpPatternImpl: <\g'name'>
+    RegExpBranchImpl: <\g'name'>
+      RegExpNamedGroupRefImpl: <\g'name'>
+        PsiElement(RUBY_QUOTED_NAMED_GROUP_CALL)('\g'')
+        PsiElement(NAME)('name')
+        PsiElement(QUOTE)(''')
\ No newline at end of file
diff --git a/RegExpSupport/testData/psi/Groups39.txt b/RegExpSupport/testData/psi/Groups39.txt
new file mode 100644
index 000000000000..60bd9b26a375
--- /dev/null
+++ b/RegExpSupport/testData/psi/Groups39.txt
@@ -0,0 +1,53 @@
+REGEXP_FILE
+  RegExpPatternImpl: <(?(name)yes-pattern|no-pattern)>
+    RegExpBranchImpl: <(?(name)yes-pattern|no-pattern)>
+      RegExpPyCondRefImpl: <(?(name)yes-pattern|no-pattern)>
+        PsiElement(PYTHON_COND_REF)('(?(')
+        PsiElement(NAME)('name')
+        PsiElement(GROUP_END)(')')
+        RegExpBranchImpl: <yes-pattern>
+          RegExpCharImpl: <y>
+            PsiElement(CHARACTER)('y')
+          RegExpCharImpl: <e>
+            PsiElement(CHARACTER)('e')
+          RegExpCharImpl: <s>
+            PsiElement(CHARACTER)('s')
+          RegExpCharImpl: <->
+            PsiElement(MINUS)('-')
+          RegExpCharImpl: <p>
+            PsiElement(CHARACTER)('p')
+          RegExpCharImpl: <a>
+            PsiElement(CHARACTER)('a')
+          RegExpCharImpl: <t>
+            PsiElement(CHARACTER)('t')
+          RegExpCharImpl: <t>
+            PsiElement(CHARACTER)('t')
+          RegExpCharImpl: <e>
+            PsiElement(CHARACTER)('e')
+          RegExpCharImpl: <r>
+            PsiElement(CHARACTER)('r')
+          RegExpCharImpl: <n>
+            PsiElement(CHARACTER)('n')
+        PsiElement(UNION)('|')
+        RegExpBranchImpl: <no-pattern>
+          RegExpCharImpl: <n>
+            PsiElement(CHARACTER)('n')
+          RegExpCharImpl: <o>
+            PsiElement(CHARACTER)('o')
+          RegExpCharImpl: <->
+            PsiElement(MINUS)('-')
+          RegExpCharImpl: <p>
+            PsiElement(CHARACTER)('p')
+          RegExpCharImpl: <a>
+            PsiElement(CHARACTER)('a')
+          RegExpCharImpl: <t>
+            PsiElement(CHARACTER)('t')
+          RegExpCharImpl: <t>
+            PsiElement(CHARACTER)('t')
+          RegExpCharImpl: <e>
+            PsiElement(CHARACTER)('e')
+          RegExpCharImpl: <r>
+            PsiElement(CHARACTER)('r')
+          RegExpCharImpl: <n>
+            PsiElement(CHARACTER)('n')
+        PsiElement(GROUP_END)(')')
\ No newline at end of file
diff --git a/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceIndexUtil.java b/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceIndexUtil.java
index 09314d8059ba..869eedc77d1c 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceIndexUtil.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceIndexUtil.java
@@ -26,7 +26,7 @@ import java.util.*;
 
 public class BackwardReferenceIndexUtil {
   static void registerFile(String filePath,
-                           Set<? extends JavacRef> refs,
+                           Collection<? extends JavacRef> refs,
                            List<JavacDef> defs,
                            final BackwardReferenceIndexWriter writer) {
     final int fileId = writer.enumeratePath(filePath);
diff --git a/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceRegistrar.java b/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceRegistrar.java
index 891572268ccd..b6fb8ee5177a 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceRegistrar.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/backwardRefs/BackwardReferenceRegistrar.java
@@ -19,16 +19,20 @@ import org.jetbrains.jps.javac.ast.api.JavacDef;
 import org.jetbrains.jps.javac.ast.api.JavacFileReferencesRegistrar;
 import org.jetbrains.jps.javac.ast.api.JavacRef;
 
+import java.util.Collection;
 import java.util.List;
-import java.util.Set;
 
 public class BackwardReferenceRegistrar implements JavacFileReferencesRegistrar {
-  private BackwardReferenceIndexWriter myWriter;
+  private volatile BackwardReferenceIndexWriter myWriter;
 
   @Override
-  public boolean initialize() {
+  public void initialize() {
     myWriter = BackwardReferenceIndexWriter.getInstance();
-    return myWriter != null;
+  }
+
+  @Override
+  public boolean isEnabled() {
+    return BackwardReferenceIndexWriter.isEnabled();
   }
 
   @Override
@@ -37,7 +41,7 @@ public class BackwardReferenceRegistrar implements JavacFileReferencesRegistrar
   }
 
   @Override
-  public void registerFile(String filePath, Set<? extends JavacRef> refs, List<JavacDef> defs) {
+  public void registerFile(String filePath, Collection<JavacRef> refs, List<JavacDef> defs) {
     BackwardReferenceIndexUtil.registerFile(filePath, refs, defs, myWriter);
   }
 }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java b/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java
index 46dea9b6a6aa..400adc6de8f5 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/incremental/java/JavaBuilder.java
@@ -1042,6 +1042,10 @@ public class JavaBuilder extends ModuleLevelBuilder {
       }
     }
 
+    for (JavaCompilerToolExtension extension : JavaCompilerToolExtension.getExtensions()) {
+      vmOptions.addAll(extension.getExternalBuildProcessOptions(compilingTool));
+    }
+
     compilingTool.processCompilerOptions(context, options);
 
     JAVAC_OPTIONS.set(context, options);
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/JavaCompilerToolExtension.java b/jps/jps-builders/src/org/jetbrains/jps/javac/JavaCompilerToolExtension.java
index 92502508366a..650c67b0a87e 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/javac/JavaCompilerToolExtension.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/JavaCompilerToolExtension.java
@@ -22,6 +22,8 @@ import org.jetbrains.jps.service.JpsServiceManager;
 
 import javax.tools.*;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 
 /**
  * @author Eugene Zhuravlev
@@ -51,6 +53,10 @@ public abstract class JavaCompilerToolExtension {
   public void processData(String dataName, byte[] content) {
   }
 
+  public List<String> getExternalBuildProcessOptions(@NotNull JavaCompilingTool compilingTool) {
+    return Collections.emptyList();
+  }
+
   public static Iterable<JavaCompilerToolExtension> getExtensions() {
     return JpsServiceManager.getInstance().getExtensions(JavaCompilerToolExtension.class);
   }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferenceCollectorListener.java b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferenceCollectorListener.java
index 18e1d728961c..0231eb25ab84 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferenceCollectorListener.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferenceCollectorListener.java
@@ -15,6 +15,7 @@
  */
 package org.jetbrains.jps.javac.ast;
 
+import com.intellij.util.Consumer;
 import com.intellij.util.ReflectionUtil;
 import com.sun.source.util.JavacTask;
 import com.sun.source.util.TaskEvent;
@@ -27,7 +28,7 @@ import gnu.trove.THashMap;
 import gnu.trove.THashSet;
 import gnu.trove.TObjectHashingStrategy;
 import org.jetbrains.jps.javac.ast.api.JavacDef;
-import org.jetbrains.jps.javac.ast.api.JavacFileReferencesRegistrar;
+import org.jetbrains.jps.javac.ast.api.JavacFileData;
 import org.jetbrains.jps.javac.ast.api.JavacRef;
 
 import javax.lang.model.element.ElementKind;
@@ -35,14 +36,11 @@ import javax.lang.model.element.TypeElement;
 import javax.tools.*;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 
 final class JavacReferenceCollectorListener implements TaskListener {
-  private final JavacFileReferencesRegistrar[] myFullASTListeners;
-  private final JavacFileReferencesRegistrar[] myOnlyImportsListeners;
+  private final boolean myDivideImportRefs;
+  private final Consumer<JavacFileData> myDataConsumer;
   private final JavacTreeRefScanner myAstScanner;
 
   private Name myAsterisk;
@@ -50,11 +48,11 @@ final class JavacReferenceCollectorListener implements TaskListener {
   private final Map<String, IncompletelyProcessedFile> myIncompletelyProcessedFiles = new THashMap<String, IncompletelyProcessedFile>(10);
 
   static void installOn(JavaCompiler.CompilationTask task,
-                        JavacFileReferencesRegistrar[] fullASTListenerArray,
-                        JavacFileReferencesRegistrar[] onlyImportsListenerArray) {
+                        boolean divideImportRefs,
+                        Consumer<JavacFileData> dataConsumer) {
     JavacTask javacTask = (JavacTask)task;
     Method addTaskMethod = ReflectionUtil.getMethod(JavacTask.class, "addTaskListener", TaskListener.class); // jdk >= 8
-    final JavacReferenceCollectorListener taskListener = new JavacReferenceCollectorListener(fullASTListenerArray, onlyImportsListenerArray);
+    final JavacReferenceCollectorListener taskListener = new JavacReferenceCollectorListener(divideImportRefs, dataConsumer);
     if (addTaskMethod != null) {
       try {
         addTaskMethod.invoke(task, taskListener);
@@ -71,9 +69,9 @@ final class JavacReferenceCollectorListener implements TaskListener {
     }
   }
 
-  private JavacReferenceCollectorListener(JavacFileReferencesRegistrar[] fullASTListenerArray, JavacFileReferencesRegistrar[] importsListenerArray) {
-    myFullASTListeners = fullASTListenerArray;
-    myOnlyImportsListeners = importsListenerArray;
+  private JavacReferenceCollectorListener(boolean divideImportRefs, Consumer<JavacFileData> dataConsumer) {
+    myDivideImportRefs = divideImportRefs;
+    myDataConsumer = dataConsumer;
     myAstScanner = JavacTreeRefScanner.createASTScanner();
   }
 
@@ -93,37 +91,32 @@ final class JavacReferenceCollectorListener implements TaskListener {
         final int size = declarations.size();
 
         boolean isFileDataComplete = true;
-        boolean submitImportsOnlyData = true;
+        boolean collectImportsData = true;
         JCTree declarationToProcess = null;
-        final Set<JavacRef.JavacSymbolRefBase> collectedReferences;
-        final List<JavacDef> collectedDefinitions;
         final TypeElement analyzedElement = e.getTypeElement();
 
+        IncompletelyProcessedFile incompletelyProcessedFile;
         switch (size) {
           case 0:
-            collectedReferences = IncompletelyProcessedFile.createReferenceHolder();
-            collectedDefinitions = IncompletelyProcessedFile.createDefinitionHolder();
+            incompletelyProcessedFile = new IncompletelyProcessedFile(0, fileName);
             break;
           case 1:
-            collectedReferences = IncompletelyProcessedFile.createReferenceHolder();
-            collectedDefinitions = IncompletelyProcessedFile.createDefinitionHolder();
+            incompletelyProcessedFile = new IncompletelyProcessedFile(0, fileName);
             declarationToProcess = declarations.get(0);
             break;
           default:
-            IncompletelyProcessedFile incompletelyProcessedFile = myIncompletelyProcessedFiles.get(fileName);
+            incompletelyProcessedFile = myIncompletelyProcessedFiles.get(fileName);
             if (incompletelyProcessedFile == null) {
-              myIncompletelyProcessedFiles.put(fileName, incompletelyProcessedFile = new IncompletelyProcessedFile(size));
+              myIncompletelyProcessedFiles.put(fileName, incompletelyProcessedFile = new IncompletelyProcessedFile(size, fileName));
             } else {
-              submitImportsOnlyData = false;
+              collectImportsData = false;
             }
 
-            if (--incompletelyProcessedFile.remainDeclarations == 0) {
+            if (incompletelyProcessedFile.decrementRemainDeclarationsAndGet() == 0) {
               myIncompletelyProcessedFiles.remove(fileName);
             } else {
               isFileDataComplete = false;
             }
-            collectedReferences = incompletelyProcessedFile.collectedReferences;
-            collectedDefinitions = incompletelyProcessedFile.collectedDefinitions;
 
             for (JCTree declaration : declarations) {
               if (declaration.type != null && declaration.type.tsym == analyzedElement) {
@@ -135,22 +128,22 @@ final class JavacReferenceCollectorListener implements TaskListener {
             if (declarationToProcess == null) throw new IllegalStateException("Can't find tree for " + analyzedElement.getQualifiedName());
         }
 
-        if (submitImportsOnlyData) {
-          scanImports(unit, collectedReferences);
-          for (JavacFileReferencesRegistrar r : myOnlyImportsListeners) {
-            r.registerFile(fileName, collectedReferences, collectedDefinitions);
+        if (collectImportsData) {
+          scanImports(unit, incompletelyProcessedFile.myFileData.getRefs());
+          if (myDivideImportRefs) {
+            scanImports(unit, incompletelyProcessedFile.myFileData.getImportRefs());
           }
         }
-        if (myFullASTListeners.length == 0) return;
+        final IncompletelyProcessedFile finalIncompletelyProcessedFile = incompletelyProcessedFile;
         JavacTreeScannerSink sink = new JavacTreeScannerSink() {
           @Override
           public void sinkReference(JavacRef.JavacSymbolRefBase ref) {
-            collectedReferences.add(ref);
+            finalIncompletelyProcessedFile.myFileData.getRefs().add(ref);
           }
 
           @Override
           public void sinkDeclaration(JavacDef def) {
-            collectedDefinitions.add(def);
+            finalIncompletelyProcessedFile.myFileData.getDefs().add(def);
           }
         };
         myAstScanner.scan(declarationToProcess, sink);
@@ -160,9 +153,7 @@ final class JavacReferenceCollectorListener implements TaskListener {
             myAstScanner.scan(annotation, sink);
           }
 
-          for (JavacFileReferencesRegistrar r : myFullASTListeners) {
-            r.registerFile(e.getSourceFile().getName(), collectedReferences, collectedDefinitions);
-          }
+          myDataConsumer.consume(incompletelyProcessedFile.myFileData);
         }
       }
     }
@@ -178,7 +169,7 @@ final class JavacReferenceCollectorListener implements TaskListener {
     return myAsterisk;
   }
 
-  private void scanImports(JCTree.JCCompilationUnit compilationUnit, Set<JavacRef.JavacSymbolRefBase> symbols) {
+  private void scanImports(JCTree.JCCompilationUnit compilationUnit, Collection<JavacRef> symbols) {
     for (JCTree.JCImport anImport : compilationUnit.getImports()) {
       final JCTree.JCFieldAccess id = (JCTree.JCFieldAccess)anImport.getQualifiedIdentifier();
       final Symbol sym = id.sym;
@@ -205,7 +196,7 @@ final class JavacReferenceCollectorListener implements TaskListener {
     }
   }
 
-  private static void collectClassImports(Symbol baseImport, Set<JavacRef.JavacSymbolRefBase> collector) {
+  private static void collectClassImports(Symbol baseImport, Collection<JavacRef> collector) {
     for (Symbol symbol = baseImport;
          symbol != null && symbol.getKind() != ElementKind.PACKAGE;
          symbol = symbol.owner) {
@@ -213,31 +204,38 @@ final class JavacReferenceCollectorListener implements TaskListener {
     }
   }
 
-  private static class IncompletelyProcessedFile {
-    private final Set<JavacRef.JavacSymbolRefBase> collectedReferences = createReferenceHolder();
-    private final List<JavacDef> collectedDefinitions = createDefinitionHolder();
-    private int remainDeclarations;
+  private class IncompletelyProcessedFile {
+    private final JavacFileData myFileData;
+    private int myRemainDeclarations;
 
-    private IncompletelyProcessedFile(int remainDeclarations) {
-      this.remainDeclarations = remainDeclarations;
+    private IncompletelyProcessedFile(int remainDeclarations, String filePath) {
+      myRemainDeclarations = remainDeclarations;
+      myFileData = new JavacFileData(filePath,
+                                     createReferenceHolder(),
+                                     myDivideImportRefs ? createReferenceHolder() : Collections.<JavacRef>emptyList(),
+                                     createDefinitionHolder());
     }
 
-    private static Set<JavacRef.JavacSymbolRefBase> createReferenceHolder() {
-      return new THashSet<JavacRef.JavacSymbolRefBase>(new TObjectHashingStrategy<JavacRef.JavacSymbolRefBase>() {
-        @Override
-        public int computeHashCode(JavacRef.JavacSymbolRefBase ref) {
-          return ref.getOriginalElement().hashCode();
-        }
-
-        @Override
-        public boolean equals(JavacRef.JavacSymbolRefBase r1, JavacRef.JavacSymbolRefBase r2) {
-          return r1.getOriginalElement() == r2.getOriginalElement();
-        }
-      });
-    }
-
-    private static List<JavacDef> createDefinitionHolder() {
-      return new ArrayList<JavacDef>();
+    private int decrementRemainDeclarationsAndGet() {
+      return --myRemainDeclarations;
     }
   }
+
+  private static Set<JavacRef> createReferenceHolder() {
+    return new THashSet<JavacRef>(new TObjectHashingStrategy<JavacRef>() {
+      @Override
+      public int computeHashCode(JavacRef ref) {
+        return ((JavacRef.JavacSymbolRefBase) ref).getOriginalElement().hashCode();
+      }
+
+      @Override
+      public boolean equals(JavacRef r1, JavacRef r2) {
+        return ((JavacRef.JavacSymbolRefBase) r1).getOriginalElement() == ((JavacRef.JavacSymbolRefBase) r2).getOriginalElement();
+      }
+    });
+  }
+
+  private static List<JavacDef> createDefinitionHolder() {
+    return new ArrayList<JavacDef>();
+  }
 }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferencesCollector.java b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferencesCollector.java
index 7830dd894fa5..f61438b4fcab 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferencesCollector.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/JavacReferencesCollector.java
@@ -15,34 +15,19 @@
  */
 package org.jetbrains.jps.javac.ast;
 
-import com.intellij.util.SmartList;
-import org.jetbrains.jps.javac.ast.api.JavacFileReferencesRegistrar;
-import org.jetbrains.jps.service.JpsServiceManager;
+import com.intellij.util.Consumer;
+import org.jetbrains.jps.javac.ast.api.JavacFileData;
 
 import javax.tools.*;
-import java.util.List;
 
 /**
  * Code here should not depend on any javac private API located in tools.jar if no JavacFileReferencesRegistrar-s will be run.
  * A workaround to allow run standalone jps with improperly configured classloader without NoClassDefFoundError (e.g: IDEA-162877)
  */
 public class JavacReferencesCollector {
-  public static void installOn(JavaCompiler.CompilationTask task) {
-    List<JavacFileReferencesRegistrar> fullASTListeners = new SmartList<JavacFileReferencesRegistrar>();
-    List<JavacFileReferencesRegistrar> onlyImportsListeners = new SmartList<JavacFileReferencesRegistrar>();
-    for (JavacFileReferencesRegistrar listener : JpsServiceManager.getInstance().getExtensions(JavacFileReferencesRegistrar.class)) {
-      if (!listener.initialize()) {
-        continue;
-      }
-      (listener.onlyImports() ? onlyImportsListeners : fullASTListeners).add(listener);
-    }
-
-    final JavacFileReferencesRegistrar[] fullASTListenerArray = fullASTListeners.toArray(new JavacFileReferencesRegistrar[fullASTListeners.size()]);
-    final JavacFileReferencesRegistrar[] onlyImportsListenerArray = onlyImportsListeners.toArray(new JavacFileReferencesRegistrar[onlyImportsListeners.size()]);
-    if (fullASTListenerArray.length == 0 && onlyImportsListenerArray.length == 0) {
-      return;
-    }
-
-    JavacReferenceCollectorListener.installOn(task, fullASTListenerArray, onlyImportsListenerArray);
+  public static void installOn(JavaCompiler.CompilationTask task,
+                               boolean divideImportRefs,
+                               Consumer<JavacFileData> fileDataConsumer) {
+    JavacReferenceCollectorListener.installOn(task, divideImportRefs, fileDataConsumer);
   }
 }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/RefCollectorCompilerToolExtension.java b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/RefCollectorCompilerToolExtension.java
index e45c0dd9021a..ee37c8d88400 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/RefCollectorCompilerToolExtension.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/RefCollectorCompilerToolExtension.java
@@ -15,14 +15,23 @@
  */
 package org.jetbrains.jps.javac.ast;
 
+import com.intellij.openapi.util.AtomicClearableLazyValue;
+import com.intellij.util.Consumer;
+import com.intellij.util.SystemProperties;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.TestOnly;
 import org.jetbrains.jps.builders.java.JavaCompilingTool;
 import org.jetbrains.jps.javac.DiagnosticOutputConsumer;
 import org.jetbrains.jps.javac.JavaCompilerToolExtension;
+import org.jetbrains.jps.javac.ast.api.JavacFileData;
+import org.jetbrains.jps.javac.ast.api.JavacFileReferencesRegistrar;
 import org.jetbrains.jps.model.java.compiler.JavaCompilers;
+import org.jetbrains.jps.service.JpsServiceManager;
 
 import javax.tools.*;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 
 /**
  * @author Eugene Zhuravlev
@@ -31,6 +40,24 @@ import java.util.Collection;
 public class RefCollectorCompilerToolExtension extends JavaCompilerToolExtension{
   public static final String ID = "ASTReferenceCollector";
 
+  private static final String ENABLED_PARAM = "jps.ref.collector.enabled";
+  private static final String DIVIDE_IMPORTS_PARAM = "jps.divide.imports";
+
+  private final AtomicClearableLazyValue<List<JavacFileReferencesRegistrar>> myRegistrars = new AtomicClearableLazyValue<List<JavacFileReferencesRegistrar>>() {
+    @NotNull
+    @Override
+    protected List<JavacFileReferencesRegistrar> compute() {
+      List<JavacFileReferencesRegistrar> result = new ArrayList<JavacFileReferencesRegistrar>();
+      for (JavacFileReferencesRegistrar registrar : JpsServiceManager.getInstance().getExtensions(JavacFileReferencesRegistrar.class)) {
+        if (registrar.isEnabled()) {
+          registrar.initialize();
+          result.add(registrar);
+        }
+      }
+      return result;
+    }
+  };
+
   @NotNull
   @Override
   public String getId() {
@@ -41,15 +68,94 @@ public class RefCollectorCompilerToolExtension extends JavaCompilerToolExtension
   public void beforeCompileTaskExecution(@NotNull JavaCompilingTool compilingTool,
                                          @NotNull JavaCompiler.CompilationTask task,
                                          @NotNull Collection<String> options,
-                                         @NotNull DiagnosticOutputConsumer diagnosticConsumer) {
-    // todo: transfer collected data via DiagnosticOutputConsumer.customOutputData()
-    if (JavaCompilers.JAVAC_ID.equals(compilingTool.getId())) {
-      JavacReferencesCollector.installOn(task);
+                                         @NotNull final DiagnosticOutputConsumer diagnosticConsumer) {
+    if (isJavac(compilingTool)) {
+      final String isEnabledProperty = System.getProperty(ENABLED_PARAM);
+
+      Consumer<JavacFileData> fileDataConsumer;
+      boolean divideImportsRefs;
+      if (isEnabledProperty == null) {
+        //in-process
+        final RefCollectorOptions refCollectorOptions = new RefCollectorOptions();
+        fileDataConsumer = refCollectorOptions.enabled ? new Consumer<JavacFileData>() {
+          @Override
+          public void consume(JavacFileData data) {
+            submitFileData(data);
+          }
+        } : null;
+        divideImportsRefs = refCollectorOptions.divideImportRefs;
+      } else if (isEnabledProperty.equals("true")) {
+        //external
+        fileDataConsumer = new Consumer<JavacFileData>() {
+          @Override
+          public void consume(JavacFileData data) {
+            diagnosticConsumer.customOutputData(ID, "javac-refs", data.asBytes());
+          }
+        };
+        divideImportsRefs = SystemProperties.getBooleanProperty(DIVIDE_IMPORTS_PARAM, false);
+      } else {
+        return;
+      }
+
+      if (fileDataConsumer != null) {
+        JavacReferencesCollector.installOn(task, divideImportsRefs, fileDataConsumer);
+      }
     }
   }
 
+  @Override
+  public List<String> getExternalBuildProcessOptions(@NotNull JavaCompilingTool compilingTool) {
+    List<String> options = new ArrayList<String>(2);
+    if (isJavac(compilingTool)) {
+      final RefCollectorOptions refCollectorOptions = new RefCollectorOptions();
+      options.add("-D" + ENABLED_PARAM + "=" + refCollectorOptions.enabled);
+      if (refCollectorOptions.enabled && refCollectorOptions.divideImportRefs) {
+        options.add("-D" + DIVIDE_IMPORTS_PARAM + "=true");
+      }
+    } else {
+      options.add("-D" + ENABLED_PARAM + "=false");
+    }
+    return options;
+  }
+
   @Override
   public void processData(String dataName, byte[] content) {
-    // todo!
+    submitFileData(JavacFileData.fromBytes(content));
+  }
+
+  private void submitFileData(@NotNull JavacFileData data) {
+    for (JavacFileReferencesRegistrar registrar : myRegistrars.getValue()) {
+      registrar.registerFile(data.getFilePath(), registrar.onlyImports() ? data.getImportRefs() : data.getRefs(), data.getDefs());
+    }
+  }
+
+  private static boolean isJavac(@NotNull JavaCompilingTool compilingTool) {
+    return JavaCompilers.JAVAC_ID.equals(compilingTool.getId());
+  }
+
+  private static class RefCollectorOptions {
+    private final boolean enabled;
+    private final boolean divideImportRefs;
+
+    private RefCollectorOptions() {
+      boolean enabled = false;
+      boolean divideImportRefs = false;
+      for (JavacFileReferencesRegistrar listener : JpsServiceManager.getInstance().getExtensions(JavacFileReferencesRegistrar.class)) {
+        if (listener.isEnabled()) {
+          enabled = true;
+          if (listener.onlyImports()) {
+            divideImportRefs = true;
+          }
+        }
+      }
+
+      this.enabled = enabled;
+      this.divideImportRefs = divideImportRefs;
+    }
+  }
+
+  @TestOnly
+  public void clearRegistrars() {
+    myRegistrars.drop();
   }
 }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacFileData.java b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacFileData.java
new file mode 100644
index 000000000000..364cf25b0b85
--- /dev/null
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacFileData.java
@@ -0,0 +1,247 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jetbrains.jps.javac.ast.api;
+
+import com.intellij.openapi.util.ThrowableComputable;
+import com.intellij.openapi.util.io.BufferExposingByteArrayOutputStream;
+import com.intellij.util.ThrowableConsumer;
+import com.intellij.util.io.*;
+import com.intellij.util.io.DataOutputStream;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.*;
+import java.util.Collection;
+import java.util.List;
+
+public class JavacFileData {
+  private final String myFilePath;
+  private final Collection<JavacRef> myRefs;
+  private final Collection<JavacRef> myImportRefs;
+  private final List<JavacDef> myDefs;
+
+  public JavacFileData(@NotNull String path,
+                       @NotNull Collection<JavacRef> refs,
+                       @NotNull Collection<JavacRef> importRefs,
+                       @NotNull List<JavacDef> defs) {
+    myFilePath = path;
+    myRefs = refs;
+    myImportRefs = importRefs;
+    myDefs = defs;
+  }
+
+  @NotNull
+  public String getFilePath() {
+    return myFilePath;
+  }
+
+  @NotNull
+  public Collection<JavacRef> getRefs() {
+    return myRefs;
+  }
+
+  @NotNull
+  public Collection<JavacRef> getImportRefs() {
+    return myImportRefs;
+  }
+
+  @NotNull
+  public List<JavacDef> getDefs() {
+    return myDefs;
+  }
+
+  @NotNull
+  public byte[] asBytes() {
+    final BufferExposingByteArrayOutputStream os = new BufferExposingByteArrayOutputStream();
+    DataOutputStream stream = new DataOutputStream(os);
+    try {
+      EXTERNALIZER.save(stream, this);
+    }
+    catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+    return os.toByteArray();
+  }
+
+  @NotNull
+  public static JavacFileData fromBytes(byte[] bytes) {
+    final UnsyncByteArrayInputStream is = new UnsyncByteArrayInputStream(bytes);
+    try {
+      return EXTERNALIZER.read(new DataInputStream(is));
+    }
+    catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  private static final DataExternalizer<JavacFileData> EXTERNALIZER = new DataExternalizer<JavacFileData>() {
+    DataExternalizer<JavacRef> myRefSeqExternalizer = createRefExternalizer();
+    DataExternalizer<JavacDef> myDefSeqExternalizer = createDefExternalizer();
+
+    @Override
+    public void save(@NotNull DataOutput out, JavacFileData data) throws IOException {
+      EnumeratorStringDescriptor.INSTANCE.save(out, data.getFilePath());
+      saveRefs(out, data.getRefs());
+      saveRefs(out, data.getImportRefs());
+      saveDefs(out, data.getDefs());
+    }
+
+    @Override
+    public JavacFileData read(@NotNull DataInput in) throws IOException {
+      return new JavacFileData(EnumeratorStringDescriptor.INSTANCE.read(in),
+                               readRefs(in),
+                               readRefs(in),
+                               readDefs(in));
+    }
+
+
+    private void saveRefs(final DataOutput out, Collection<JavacRef> refs) throws IOException {
+      DataInputOutputUtil.writeSeq(out, refs, new ThrowableConsumer<JavacRef, IOException>() {
+        @Override
+        public void consume(JavacRef ref) throws IOException {
+          myRefSeqExternalizer.save(out, ref);
+        }
+      });
+    }
+
+    private Collection<JavacRef> readRefs(final DataInput in) throws IOException {
+      return DataInputOutputUtil.readSeq(in, new ThrowableComputable<JavacRef, IOException>() {
+        @Override
+        public JavacRef compute() throws IOException {
+          return myRefSeqExternalizer.read(in);
+        }
+      });
+    }
+
+    private void saveDefs(final DataOutput out, List<JavacDef> defs) throws IOException {
+      DataInputOutputUtil.writeSeq(out, defs, new ThrowableConsumer<JavacDef, IOException>() {
+        @Override
+        public void consume(JavacDef def) throws IOException {
+          myDefSeqExternalizer.save(out, def);
+        }
+      });
+    }
+
+    private List<JavacDef> readDefs(final DataInput in) throws IOException {
+      return DataInputOutputUtil.readSeq(in, new ThrowableComputable<JavacDef, IOException>() {
+        @Override
+        public JavacDef compute() throws IOException {
+          return myDefSeqExternalizer.read(in);
+        }
+      });
+    }
+
+  };
+
+  private static DataExternalizer<JavacDef> createDefExternalizer() {
+    return new DataExternalizer<JavacDef>() {
+      private static final byte CLASS_MARKER = 0;
+      private static final byte FUN_EXPR_MARKER = 1;
+
+      DataExternalizer<JavacRef> refExternalizer = createRefExternalizer();
+
+      @Override
+      public void save(@NotNull DataOutput out, JavacDef def) throws IOException {
+        if (def instanceof JavacDef.JavacClassDef) {
+          out.writeByte(CLASS_MARKER);
+          final JavacRef[] superClasses = ((JavacDef.JavacClassDef)def).getSuperClasses();
+          out.writeInt(superClasses.length);
+          for (JavacRef aClass : superClasses) {
+            refExternalizer.save(out, aClass);
+          }
+        }
+        else if (def instanceof JavacDef.JavacFunExprDef) {
+          out.writeByte(FUN_EXPR_MARKER);
+        } else {
+          throw new IllegalStateException("unknown type: " + def.getClass());
+        }
+        refExternalizer.save(out, def.getDefinedElement());
+      }
+
+      @Override
+      public JavacDef read(@NotNull DataInput in) throws IOException {
+        final byte marker = in.readByte();
+        switch (marker) {
+          case CLASS_MARKER:
+            final int supersSize = in.readInt();
+            JavacRef[] superClasses = new JavacRef[supersSize];
+            for (int i = 0; i < supersSize; i++) {
+              superClasses[i] = refExternalizer.read(in);
+            }
+            return new JavacDef.JavacClassDef(refExternalizer.read(in), superClasses);
+          case FUN_EXPR_MARKER:
+            return new JavacDef.JavacFunExprDef(refExternalizer.read(in));
+          default: throw new IllegalStateException("unknown marker " + marker);
+        }
+      }
+    };
+  }
+
+  private static DataExternalizer<JavacRef> createRefExternalizer() {
+    return new DataExternalizer<JavacRef>() {
+      private static final byte CLASS_MARKER = 0;
+      private static final byte METHOD_MARKER = 1;
+      private static final byte FIELD_MARKER = 2;
+
+      @Override
+      public void save(@NotNull DataOutput out, JavacRef ref) throws IOException {
+        if (ref instanceof JavacRef.JavacClass) {
+          out.writeByte(CLASS_MARKER);
+          out.writeBoolean(((JavacRef.JavacClass)ref).isAnonymous());
+        }
+        else if (ref instanceof JavacRef.JavacField) {
+          out.writeByte(FIELD_MARKER);
+          writeBytes(out, ref.getOwnerName());
+        }
+        else if (ref instanceof JavacRef.JavacMethod) {
+          out.writeByte(METHOD_MARKER);
+          writeBytes(out, ref.getOwnerName());
+          out.write(((JavacRef.JavacMethod)ref).getParamCount());
+        } else {
+          throw new IllegalStateException("unknown type: " + ref.getClass());
+        }
+        out.writeLong(ref.getFlags());
+        writeBytes(out, ref.getName());
+      }
+
+      @Override
+      public JavacRef read(@NotNull DataInput in) throws IOException {
+        final byte marker = in.readByte();
+        switch (marker) {
+          case CLASS_MARKER:
+            return new JavacRef.JavacClassImpl(in.readBoolean(), in.readLong(), readBytes(in));
+          case METHOD_MARKER:
+            return new JavacRef.JavacMethodImpl(readBytes(in), in.readByte(), in.readLong(), readBytes(in));
+          case FIELD_MARKER:
+            return new JavacRef.JavacFieldImpl(readBytes(in), in.readLong(), readBytes(in));
+          default:
+            throw new IllegalStateException("unknown marker " + marker);
+        }
+      }
+
+      private void writeBytes(DataOutput out, byte[] bytes) throws IOException {
+        out.writeInt(bytes.length);
+        out.write(bytes);
+      }
+
+      private byte[] readBytes(DataInput in) throws IOException {
+        final int len = in.readInt();
+        final byte[] buf = new byte[len];
+        in.readFully(buf);
+        return buf;
+      }
+    };
+  }
+}
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacFileReferencesRegistrar.java b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacFileReferencesRegistrar.java
index e5106fd5a223..7ac2534c95fd 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacFileReferencesRegistrar.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacFileReferencesRegistrar.java
@@ -15,14 +15,15 @@
  */
 package org.jetbrains.jps.javac.ast.api;
 
+import java.util.Collection;
 import java.util.List;
-import java.util.Set;
 
 public interface JavacFileReferencesRegistrar {
+  void initialize();
 
-  boolean initialize();
+  boolean isEnabled();
 
   boolean onlyImports();
 
-  void registerFile(String filePath, Set<? extends JavacRef> refs, List<JavacDef> defs);
+  void registerFile(String filePath, Collection<JavacRef> refs, List<JavacDef> defs);
 }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacRef.java b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacRef.java
index ed141386cd09..a7c532cfb3dc 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacRef.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/ast/api/JavacRef.java
@@ -16,6 +16,7 @@
 package org.jetbrains.jps.javac.ast.api;
 
 import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.util.Convert;
 import org.jetbrains.annotations.NotNull;
 
 public interface JavacRef {
@@ -64,7 +65,7 @@ public interface JavacRef {
   class JavacClassImpl extends JavacRefBase implements JavacClass {
     private boolean myAnonymous;
 
-    public JavacClassImpl(byte[] name, long flags, boolean anonymous) {
+    public JavacClassImpl(boolean anonymous, long flags, byte[] name) {
       super(name, flags);
       myAnonymous = anonymous;
     }
@@ -78,13 +79,18 @@ public interface JavacRef {
     public boolean isAnonymous() {
       return myAnonymous;
     }
+
+    @Override
+    public String toString() {
+      return Convert.utf2string(getName());
+    }
   }
 
   class JavacMethodImpl extends JavacRefBase implements JavacMethod {
     private final byte[] myOwnerName;
     private final byte myParamCount;
 
-    public JavacMethodImpl(byte[] name, byte[] ownerName, byte paramCount, long flags) {
+    public JavacMethodImpl(byte[] ownerName, byte paramCount, long flags, byte[] name) {
       super(name, flags);
       myOwnerName = ownerName;
       myParamCount = paramCount;
@@ -99,12 +105,17 @@ public interface JavacRef {
     public byte[] getOwnerName() {
       return myOwnerName;
     }
+
+    @Override
+    public String toString() {
+      return Convert.utf2string(getOwnerName()) + "." + Convert.utf2string(getName()) + "(" + myParamCount + ")";
+    }
   }
 
   class JavacFieldImpl extends JavacRefBase implements JavacField {
     private final byte[] myOwnerName;
 
-    public JavacFieldImpl(byte[] name, byte[] ownerName, long flags) {
+    public JavacFieldImpl(byte[] ownerName, long flags, byte[] name) {
       super(name, flags);
       myOwnerName = ownerName;
     }
@@ -114,6 +125,11 @@ public interface JavacRef {
     public byte[] getOwnerName() {
       return myOwnerName;
     }
+
+    @Override
+    public String toString() {
+      return Convert.utf2string(getOwnerName()) + "." + Convert.utf2string(getName());
+    }
   }
 
   abstract class JavacSymbolRefBase implements JavacRef {
diff --git a/jps/jps-builders/testSrc/org/jetbrains/references/ReferenceIndexTestBase.kt b/jps/jps-builders/testSrc/org/jetbrains/references/ReferenceIndexTestBase.kt
index 602b49de9f8e..131d2c7776a3 100644
--- a/jps/jps-builders/testSrc/org/jetbrains/references/ReferenceIndexTestBase.kt
+++ b/jps/jps-builders/testSrc/org/jetbrains/references/ReferenceIndexTestBase.kt
@@ -29,9 +29,12 @@ import org.jetbrains.jps.backwardRefs.CompilerBackwardReferenceIndex
 import org.jetbrains.jps.backwardRefs.LightRef
 import org.jetbrains.jps.backwardRefs.index.CompiledFileData
 import org.jetbrains.jps.backwardRefs.index.CompilerIndices
+import org.jetbrains.jps.builders.BuildResult
 import org.jetbrains.jps.builders.JpsBuildTestCase
 import org.jetbrains.jps.builders.TestProjectBuilderLogger
 import org.jetbrains.jps.builders.logging.BuildLoggingManager
+import org.jetbrains.jps.javac.JavaCompilerToolExtension
+import org.jetbrains.jps.javac.ast.RefCollectorCompilerToolExtension
 import java.io.File
 
 abstract class ReferenceIndexTestBase : JpsBuildTestCase() {
@@ -58,6 +61,22 @@ abstract class ReferenceIndexTestBase : JpsBuildTestCase() {
     assertIndexEquals("initialIndex.txt")
   }
 
+  override fun rebuildAllModules() {
+    try {
+      super.rebuildAllModules()
+    } finally {
+      (JavaCompilerToolExtension.getExtension(RefCollectorCompilerToolExtension.ID) as RefCollectorCompilerToolExtension).clearRegistrars()
+    }
+  }
+
+  override fun buildAllModules(): BuildResult {
+    try {
+      return super.buildAllModules()
+    } finally {
+      (JavaCompilerToolExtension.getExtension(RefCollectorCompilerToolExtension.ID) as RefCollectorCompilerToolExtension).clearRegistrars()
+    }
+  }
+
   protected fun renameFile(fileToRename: String, newName: String) {
     rename(orCreateProjectDir.path + "/m/" + fileToRename, newName)
   }
diff --git a/platform/platform-impl/src/com/intellij/openapi/editor/CustomFileDropHandler.java b/platform/platform-impl/src/com/intellij/openapi/editor/CustomFileDropHandler.java
index 27090bdeb11a..600ec36b195c 100644
--- a/platform/platform-impl/src/com/intellij/openapi/editor/CustomFileDropHandler.java
+++ b/platform/platform-impl/src/com/intellij/openapi/editor/CustomFileDropHandler.java
@@ -18,6 +18,7 @@ package com.intellij.openapi.editor;
 import com.intellij.openapi.extensions.ExtensionPointName;
 import com.intellij.openapi.project.Project;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.awt.datatransfer.Transferable;
 
@@ -25,7 +26,7 @@ public abstract class CustomFileDropHandler {
   public static final ExtensionPointName<CustomFileDropHandler> CUSTOM_DROP_HANDLER_EP =
     ExtensionPointName.create("com.intellij.customFileDropHandler");
 
-  public abstract boolean canHandle(@NotNull Transferable t, Editor editor);
+  public abstract boolean canHandle(@NotNull Transferable t, @Nullable Editor editor);
 
-  public abstract boolean handleDrop(@NotNull Transferable t, Editor editor, final Project project);
+  public abstract boolean handleDrop(@NotNull Transferable t, @Nullable Editor editor, final Project project);
 }
diff --git a/platform/platform-resources/src/fonts/FiraCode-Bold.ttf b/platform/platform-resources/src/fonts/FiraCode-Bold.ttf
index 04cd794d4ee6..b919d6b711f1 100644
Binary files a/platform/platform-resources/src/fonts/FiraCode-Bold.ttf and b/platform/platform-resources/src/fonts/FiraCode-Bold.ttf differ
diff --git a/platform/platform-resources/src/fonts/FiraCode-Light.ttf b/platform/platform-resources/src/fonts/FiraCode-Light.ttf
index 33bf04fbb037..50fe033b02cf 100644
Binary files a/platform/platform-resources/src/fonts/FiraCode-Light.ttf and b/platform/platform-resources/src/fonts/FiraCode-Light.ttf differ
diff --git a/platform/platform-resources/src/fonts/FiraCode-Medium.ttf b/platform/platform-resources/src/fonts/FiraCode-Medium.ttf
index 8b113f1c2e7f..88a675052398 100644
Binary files a/platform/platform-resources/src/fonts/FiraCode-Medium.ttf and b/platform/platform-resources/src/fonts/FiraCode-Medium.ttf differ
diff --git a/platform/platform-resources/src/fonts/FiraCode-Regular.ttf b/platform/platform-resources/src/fonts/FiraCode-Regular.ttf
index d96a62a0cb27..575c21ba7ec5 100644
Binary files a/platform/platform-resources/src/fonts/FiraCode-Regular.ttf and b/platform/platform-resources/src/fonts/FiraCode-Regular.ttf differ
diff --git a/platform/platform-resources/src/fonts/FiraCode-Retina.ttf b/platform/platform-resources/src/fonts/FiraCode-Retina.ttf
index 3ff4026be699..95fbbc659584 100644
Binary files a/platform/platform-resources/src/fonts/FiraCode-Retina.ttf and b/platform/platform-resources/src/fonts/FiraCode-Retina.ttf differ
diff --git a/platform/util/src/com/intellij/openapi/util/SystemInfo.java b/platform/util/src/com/intellij/openapi/util/SystemInfo.java
index 852b5240cdb5..7629801f9df7 100644
--- a/platform/util/src/com/intellij/openapi/util/SystemInfo.java
+++ b/platform/util/src/com/intellij/openapi/util/SystemInfo.java
@@ -23,6 +23,7 @@ import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.io.File;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
@@ -57,12 +58,49 @@ public class SystemInfo extends SystemInfoRt {
   }
 
   // version numbers from http://msdn.microsoft.com/en-us/library/windows/desktop/ms724832.aspx
+  public static final boolean isWin10OrNewer = isWindows && isOsVersionAtLeast("10.0");
   public static final boolean isWin2kOrNewer = isWindows && isOsVersionAtLeast("5.0");
   public static final boolean isWinXpOrNewer = isWindows && isOsVersionAtLeast("5.1");
   public static final boolean isWinVistaOrNewer = isWindows && isOsVersionAtLeast("6.0");
   public static final boolean isWin7OrNewer = isWindows && isOsVersionAtLeast("6.1");
   public static final boolean isWin8OrNewer = isWindows && isOsVersionAtLeast("6.2");
 
+  /**
+   * https://msdn.microsoft.com/en-us/commandline/wsl/about
+   */
+  private static final AtomicNullableLazyValue<File> ourWSLBashFile = new AtomicNullableLazyValue<File>() {
+    @Nullable
+    @Override
+    protected File compute() {
+      if (!isWin10OrNewer) {
+        return null;
+      }
+
+      String windir = System.getenv().get("windir");
+      if (StringUtil.isEmpty(windir)) {
+        return null;
+      }
+
+      return new File(windir + "\\System32\\bash.exe");
+    }
+  };
+
+  /**
+   * @return WSL bash file or null if unavailable
+   */
+  @Nullable
+  public static File getWSLBashFile() {
+    File bashFile = ourWSLBashFile.getValue();
+    return bashFile == null || !bashFile.exists() ? null : bashFile;
+  }
+
+  /**
+   * @return true if we are on Windows 10+ and have WSL installed
+   */
+  public static boolean hasWSL() {
+    return getWSLBashFile() != null;
+  }
+
   public static final boolean isXWindow = isUnix && !isMac;
   // https://userbase.kde.org/KDE_System_Administration/Environment_Variables#KDE_FULL_SESSION
   public static final boolean isKDE = !StringUtil.isEmpty(System.getenv("KDE_FULL_SESSION"));
diff --git a/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/patch/PatchFileDropHandler.java b/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/patch/PatchFileDropHandler.java
index f27486b0309b..99fe2d6f919c 100644
--- a/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/patch/PatchFileDropHandler.java
+++ b/platform/vcs-impl/src/com/intellij/openapi/vcs/changes/patch/PatchFileDropHandler.java
@@ -20,6 +20,7 @@ import com.intellij.openapi.editor.CustomFileDropHandler;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.project.Project;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.awt.datatransfer.Transferable;
 import java.io.File;
@@ -28,14 +29,14 @@ import java.util.List;
 public class PatchFileDropHandler extends CustomFileDropHandler {
 
   @Override
-  public boolean canHandle(@NotNull Transferable t, Editor editor) {
+  public boolean canHandle(@NotNull Transferable t, @Nullable Editor editor) {
     List<File> list = FileCopyPasteUtil.getFileList(t);
     if (list == null || list.size() != 1) return false;
     return PatchFileType.isPatchFile(list.get(0));
   }
 
   @Override
-  public boolean handleDrop(@NotNull Transferable t, Editor editor, @NotNull final Project project) {
+  public boolean handleDrop(@NotNull Transferable t, @Nullable Editor editor, @NotNull final Project project) {
     List<File> list = FileCopyPasteUtil.getFileList(t);
     if (list == null || list.size() != 1) return false;
     return ApplyPatchAction.showAndGetApplyPatch(project, list.get(0));
diff --git a/plugins/devkit/src/inspections/quickfix/AbstractRegisterFix.java b/plugins/devkit/src/inspections/quickfix/AbstractRegisterFix.java
index dc7f8ef7ba5d..740c956c14cd 100644
--- a/plugins/devkit/src/inspections/quickfix/AbstractRegisterFix.java
+++ b/plugins/devkit/src/inspections/quickfix/AbstractRegisterFix.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2015 JetBrains s.r.o.
+ * Copyright 2000-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,7 @@ import com.intellij.codeInspection.ProblemDescriptor;
 import com.intellij.openapi.command.CommandProcessor;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.module.Module;
-import com.intellij.openapi.module.ModuleUtil;
+import com.intellij.openapi.module.ModuleUtilCore;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.ui.Messages;
 import com.intellij.openapi.util.text.StringUtil;
@@ -43,7 +43,7 @@ abstract class AbstractRegisterFix implements LocalQuickFix, DescriptorUtil.Patc
   protected final SmartPsiElementPointer<PsiClass> myPointer;
   protected static final Logger LOG = Logger.getInstance(AbstractRegisterFix.class);
 
-  public AbstractRegisterFix(@NotNull SmartPsiElementPointer<PsiClass> klass) {
+  protected AbstractRegisterFix(@NotNull SmartPsiElementPointer<PsiClass> klass) {
     myPointer = klass;
   }
 
@@ -52,6 +52,11 @@ abstract class AbstractRegisterFix implements LocalQuickFix, DescriptorUtil.Patc
     return DevKitBundle.message("inspections.component.not.registered.quickfix.family");
   }
 
+  @Override
+  public boolean startInWriteAction() {
+    return false;
+  }
+
   @NotNull
   public String getName() {
     return DevKitBundle.message("inspections.component.not.registered.quickfix.name", getType());
@@ -76,7 +81,7 @@ abstract class AbstractRegisterFix implements LocalQuickFix, DescriptorUtil.Patc
       return;
     }
     LOG.assertTrue(psiFile != null);
-    final Module module = ModuleUtil.findModuleForFile(psiFile.getVirtualFile(), project);
+    final Module module = ModuleUtilCore.findModuleForFile(psiFile.getVirtualFile(), project);
     assert module != null;
 
     Runnable command = () -> {
diff --git a/plugins/devkit/src/util/DescriptorUtil.java b/plugins/devkit/src/util/DescriptorUtil.java
index feb3fa2f4c39..57b8b2e876ea 100644
--- a/plugins/devkit/src/util/DescriptorUtil.java
+++ b/plugins/devkit/src/util/DescriptorUtil.java
@@ -15,6 +15,7 @@
  */
 package org.jetbrains.idea.devkit.util;
 
+import com.intellij.openapi.application.WriteAction;
 import com.intellij.openapi.module.Module;
 import com.intellij.openapi.vfs.ReadonlyStatusHandler;
 import com.intellij.openapi.vfs.VirtualFile;
@@ -23,6 +24,7 @@ import com.intellij.psi.PsiFile;
 import com.intellij.psi.xml.XmlFile;
 import com.intellij.psi.xml.XmlTag;
 import com.intellij.util.IncorrectOperationException;
+import com.intellij.util.ThrowableRunnable;
 import com.intellij.util.xml.DomFileElement;
 import com.intellij.util.xml.DomManager;
 import org.jetbrains.annotations.NotNull;
@@ -67,9 +69,11 @@ public class DescriptorUtil {
       throw new IncorrectOperationException(DevKitBundle.message("error.plugin.xml.readonly"));
     }
 
-    for (XmlFile pluginXml : pluginXmls) {
-      patcher.patchPluginXml(pluginXml, klass);
-    }
+    WriteAction.run((ThrowableRunnable<IncorrectOperationException>)() -> {
+      for (XmlFile pluginXml : pluginXmls) {
+        patcher.patchPluginXml(pluginXml, klass);
+      }
+    });
   }
 
   @Nullable
diff --git a/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/settings/CCOptions.java b/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/settings/CCOptions.java
index 4ebd48652970..4835ad525e01 100644
--- a/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/settings/CCOptions.java
+++ b/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/settings/CCOptions.java
@@ -5,31 +5,11 @@ import com.jetbrains.edu.learning.settings.StudyOptionsProvider;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
-import java.awt.event.ActionEvent;
-import java.awt.event.ActionListener;
 
 public class CCOptions implements StudyOptionsProvider {
   private JRadioButton myHtmlRadioButton;
   private JRadioButton myMarkdownRadioButton;
   private JPanel myPanel;
-  private boolean myIsModified = false;
-
-
-  public CCOptions() {
-    myHtmlRadioButton.addActionListener(new ActionListener() {
-      @Override
-      public void actionPerformed(ActionEvent e) {
-        myIsModified = true;
-      }
-    });
-    
-    myMarkdownRadioButton.addActionListener(new ActionListener() {
-      @Override
-      public void actionPerformed(ActionEvent e) {
-        myIsModified = true;
-      }
-    });
-  }
 
   @Nullable
   @Override
@@ -47,12 +27,15 @@ public class CCOptions implements StudyOptionsProvider {
 
   @Override
   public boolean isModified() {
-    return myIsModified;
+    final boolean htmlAsDefaultTaskFormat = CCSettings.getInstance().useHtmlAsDefaultTaskFormat();
+    return myHtmlRadioButton.isSelected() != htmlAsDefaultTaskFormat;
   }
 
   @Override
   public void apply() throws ConfigurationException {
-    CCSettings.getInstance().setUseHtmlAsDefaultTaskFormat(myHtmlRadioButton.isSelected());
+    if (isModified()) {
+      CCSettings.getInstance().setUseHtmlAsDefaultTaskFormat(myHtmlRadioButton.isSelected());
+    }
   }
 
   @Override
diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java b/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java
index 279fad1248fc..f4a264d40fff 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/StudySerializationUtils.java
@@ -476,23 +476,26 @@ public class StudySerializationUtils {
       }
 
       private static JsonObject convertSubtaskInfosToMap(JsonObject stepOptionsJson) {
-        for (JsonElement taskFileElement : stepOptionsJson.getAsJsonArray(FILES)) {
-          JsonObject taskFileObject = taskFileElement.getAsJsonObject();
-          JsonArray placeholders = taskFileObject.getAsJsonArray(PLACEHOLDERS);
-          for (JsonElement placeholder : placeholders) {
-            JsonObject placeholderObject = placeholder.getAsJsonObject();
-            JsonArray infos = placeholderObject.getAsJsonArray(SUBTASK_INFOS);
-            Map<Integer, JsonObject> objectsToInsert = new HashMap<>();
-            for (JsonElement info : infos) {
-              JsonObject object = info.getAsJsonObject();
-              int index = object.getAsJsonPrimitive(INDEX).getAsInt();
-              objectsToInsert.put(index, object);
-            }
-            placeholderObject.remove(SUBTASK_INFOS);
-            JsonObject newInfos = new JsonObject();
-            placeholderObject.add(SUBTASK_INFOS, newInfos);
-            for (Map.Entry<Integer, JsonObject> entry : objectsToInsert.entrySet()) {
-              newInfos.add(entry.getKey().toString(), entry.getValue());
+        final JsonArray files = stepOptionsJson.getAsJsonArray(FILES);
+        if (files != null) {
+          for (JsonElement taskFileElement : files) {
+            JsonObject taskFileObject = taskFileElement.getAsJsonObject();
+            JsonArray placeholders = taskFileObject.getAsJsonArray(PLACEHOLDERS);
+            for (JsonElement placeholder : placeholders) {
+              JsonObject placeholderObject = placeholder.getAsJsonObject();
+              JsonArray infos = placeholderObject.getAsJsonArray(SUBTASK_INFOS);
+              Map<Integer, JsonObject> objectsToInsert = new HashMap<>();
+              for (JsonElement info : infos) {
+                JsonObject object = info.getAsJsonObject();
+                int index = object.getAsJsonPrimitive(INDEX).getAsInt();
+                objectsToInsert.put(index, object);
+              }
+              placeholderObject.remove(SUBTASK_INFOS);
+              JsonObject newInfos = new JsonObject();
+              placeholderObject.add(SUBTASK_INFOS, newInfos);
+              for (Map.Entry<Integer, JsonObject> entry : objectsToInsert.entrySet()) {
+                newInfos.add(entry.getKey().toString(), entry.getValue());
+              }
             }
           }
         }
@@ -501,14 +504,17 @@ public class StudySerializationUtils {
 
       private static JsonObject convertToSecondVersion(JsonObject stepOptionsJson) {
         Gson gson = new GsonBuilder().setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES).create();
-        for (JsonElement taskFileElement : stepOptionsJson.getAsJsonArray(FILES)) {
-          JsonObject taskFileObject = taskFileElement.getAsJsonObject();
-          JsonArray placeholders = taskFileObject.getAsJsonArray(PLACEHOLDERS);
-          for (JsonElement placeholder : placeholders) {
-            JsonObject placeholderObject = placeholder.getAsJsonObject();
-            convertToAbsoluteOffset(taskFileObject, placeholderObject);
-            convertMultipleHints(gson, placeholderObject);
-            convertToSubtaskInfo(placeholderObject);
+        final JsonArray files = stepOptionsJson.getAsJsonArray(FILES);
+        if (files != null) {
+          for (JsonElement taskFileElement : files) {
+            JsonObject taskFileObject = taskFileElement.getAsJsonObject();
+            JsonArray placeholders = taskFileObject.getAsJsonArray(PLACEHOLDERS);
+            for (JsonElement placeholder : placeholders) {
+              JsonObject placeholderObject = placeholder.getAsJsonObject();
+              convertToAbsoluteOffset(taskFileObject, placeholderObject);
+              convertMultipleHints(gson, placeholderObject);
+              convertToSubtaskInfo(placeholderObject);
+            }
           }
         }
         return stepOptionsJson;
diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduStepicAuthorizedClient.java b/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduStepicAuthorizedClient.java
index 0760dee299e5..8d36b6626967 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduStepicAuthorizedClient.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/EduStepicAuthorizedClient.java
@@ -182,6 +182,7 @@ public class EduStepicAuthorizedClient {
     return stepicUser[0];
   }
 
+  @Nullable
   public static StepicUser login(@NotNull final String email, @NotNull final String password) {
     final List<NameValuePair> parameters = new ArrayList<>();
     if (password.isEmpty()) return null;
diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/StepicStudyOptions.java b/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/StepicStudyOptions.java
index 2e2ac1d8d221..b22afc96329b 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/StepicStudyOptions.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/stepic/StepicStudyOptions.java
@@ -16,6 +16,8 @@
 package com.jetbrains.edu.learning.stepic;
 
 import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.options.ConfigurationException;
+import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.ui.DocumentAdapter;
@@ -27,68 +29,28 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
-import javax.swing.event.ChangeEvent;
-import javax.swing.event.ChangeListener;
 import javax.swing.event.DocumentEvent;
-import javax.swing.event.DocumentListener;
 import javax.swing.text.Document;
 import javax.swing.text.PlainDocument;
-import java.awt.event.FocusEvent;
-import java.awt.event.FocusListener;
 
 public class StepicStudyOptions implements StudyOptionsProvider {
-  private static final String DEFAULT_PASSWORD_TEXT = "************";
   private static final Logger LOG = Logger.getInstance(StepicStudyOptions.class);
   private JTextField myLoginTextField;
   private JPasswordField myPasswordField;
   private JPanel myPane;
   private JBCheckBox myEnableTestingFromSamples;
 
-  private boolean myCredentialsModified;
-
   public StepicStudyOptions() {
-    myPasswordField.getDocument().addDocumentListener(new DocumentAdapter() {
+    myLoginTextField.getDocument().addDocumentListener(new DocumentAdapter() {
       @Override
       protected void textChanged(DocumentEvent e) {
-        myCredentialsModified = true;
+        erasePassword();
       }
     });
-
-    DocumentListener passwordEraser = new DocumentAdapter() {
-      @Override
-      protected void textChanged(DocumentEvent e) {
-        if (!myCredentialsModified) {
-          erasePassword();
-        }
-      }
-    };
-    myLoginTextField.getDocument().addDocumentListener(passwordEraser);
-
-    myPasswordField.addFocusListener(new FocusListener() {
-      @Override
-      public void focusGained(FocusEvent e) {
-        if (!myCredentialsModified && !getPassword().isEmpty()) {
-          erasePassword();
-        }
-      }
-
-      @Override
-      public void focusLost(FocusEvent e) {
-      }
-    });
-
-    myEnableTestingFromSamples.addChangeListener(new ChangeListener() {
-      @Override
-      public void stateChanged(ChangeEvent e) {
-        myCredentialsModified = true;
-      }
-    });
-    reset();
   }
 
   private void erasePassword() {
     setPassword("");
-    myCredentialsModified = true;
   }
 
   @NotNull
@@ -107,12 +69,15 @@ public class StepicStudyOptions implements StudyOptionsProvider {
 
   @NotNull
   private String getPassword() {
-    final String passwordText = String.valueOf(myPasswordField.getPassword());
-    return passwordText.equals(DEFAULT_PASSWORD_TEXT) ? "" : passwordText;
+    return String.valueOf(myPasswordField.getPassword());
   }
 
   private void setPassword(@NotNull final String password) {
-    myPasswordField.setText(StringUtil.isEmpty(password) ? null : password);
+    myPasswordField.setText(password);
+  }
+  
+  private boolean isTestingFromSamplesEnabled() {
+    return myEnableTestingFromSamples.isSelected();
   }
 
   @Override
@@ -122,9 +87,8 @@ public class StepicStudyOptions implements StudyOptionsProvider {
       StudyTaskManager taskManager = StudyTaskManager.getInstance(project);
       final StepicUser user = taskManager.getUser();
       setLogin(user.getEmail());
-      setPassword(DEFAULT_PASSWORD_TEXT);
+      setPassword(user.getPassword());
       myEnableTestingFromSamples.setSelected(taskManager.isEnableTestingFromSamples());
-      resetCredentialsModification();
     }
     else {
       LOG.warn("No study object is opened");
@@ -137,31 +101,42 @@ public class StepicStudyOptions implements StudyOptionsProvider {
   }
 
   @Override
-  public void apply() {
-    if (myCredentialsModified) {
-      final Project project = StudyUtils.getStudyProject();
-      if (project != null) {
-        StudyTaskManager taskManager = StudyTaskManager.getInstance(project);
-        taskManager.setEnableTestingFromSamples(myEnableTestingFromSamples.isSelected());
+  public void apply() throws ConfigurationException {
+    final Project project = StudyUtils.getStudyProject();
+    if (project != null) {
+      StudyTaskManager taskManager = StudyTaskManager.getInstance(project);
+      
+      if (isTestingFromSamplesEnabled() != taskManager.isEnableTestingFromSamples()){
+        taskManager.setEnableTestingFromSamples(isTestingFromSamplesEnabled());
+      }
+
+      final StepicUser user = taskManager.getUser();
+      final boolean isCredentialsModified = !getLogin().equals(user.getEmail()) || !getPassword().equals(user.getPassword());
+      if (isCredentialsModified) {
         final String login = getLogin();
         final String password = getPassword();
         if (!StringUtil.isEmptyOrSpaces(login) && !StringUtil.isEmptyOrSpaces(password)) {
-          final StepicUser user = taskManager.getUser();
-          user.setEmail(login);
-          user.setPassword(password);
-          
           // login to post credentials
-          final StepicUser stepicUser = EduStepicAuthorizedClient.login(login, password);
-          if (stepicUser != null) {
-            taskManager.setUser(stepicUser);
+          final StepicUser[] stepicUser = new StepicUser[1];
+          ProgressManager.getInstance().runProcessWithProgressSynchronously(
+            () -> {
+              ProgressManager.getInstance().getProgressIndicator().setIndeterminate(true);
+              stepicUser[0] = StudyUtils.execCancelable(() -> EduStepicAuthorizedClient.login(login, password));
+            }, "Logging In", true,
+            project);
+
+          if (stepicUser[0] != null && stepicUser[0].getAccessToken() != null) {
+            taskManager.setUser(stepicUser[0]);
+          }
+          else {
+            throw new ConfigurationException("Unable to login");
           }
         }
       }
-      else {
-        LOG.warn("No study object is opened");
-      }
     }
-    resetCredentialsModification();
+    else {
+      LOG.warn("No study object is opened");
+    }
   }
 
   @Nullable
@@ -171,11 +146,15 @@ public class StepicStudyOptions implements StudyOptionsProvider {
   }
 
   public boolean isModified() {
-    return myCredentialsModified;
-  }
-  
-  public void resetCredentialsModification() {
-    myCredentialsModified = false;
+    final Project project = StudyUtils.getStudyProject();
+    if (project == null) return false;
+
+    final StudyTaskManager taskManager = StudyTaskManager.getInstance(project);
+    final StepicUser user = taskManager.getUser();
+    
+    return !getLogin().equals(user.getEmail()) 
+           || !getPassword().equals(user.getPassword())
+           || !isTestingFromSamplesEnabled() == taskManager.isEnableTestingFromSamples(); 
   }
 
   private void createUIComponents() {