From 5d4e60721316c9fd90b355467b8b690a6fb5b02f Mon Sep 17 00:00:00 2001
From: "Maxim.Mossienko" <Maxim.Mossienko@jetbrains.com>
Date: Mon, 28 Jul 2014 11:31:53 +0200
Subject: [PATCH] Prevent markers from overlapping after whitespace balancing
 (WEB-12693) [a=Roman Shevchenko, r=Maxim.Mossienko]

---
 .../intellij/lang/impl/PsiBuilderImpl.java    |  8 ++++++-
 .../intellij/lang/PsiBuilderQuickTest.java    | 21 +++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/platform/core-impl/src/com/intellij/lang/impl/PsiBuilderImpl.java b/platform/core-impl/src/com/intellij/lang/impl/PsiBuilderImpl.java
index 1013565eaba5..b68fa936af23 100644
--- a/platform/core-impl/src/com/intellij/lang/impl/PsiBuilderImpl.java
+++ b/platform/core-impl/src/com/intellij/lang/impl/PsiBuilderImpl.java
@@ -1154,6 +1154,7 @@ public class PsiBuilderImpl extends UserDataHolderBase implements PsiBuilder {
   private void balanceWhiteSpaces() {
     RelativeTokenTypesView wsTokens = new RelativeTokenTypesView();
     RelativeTokenTextView tokenTextGetter = new RelativeTokenTextView();
+    int lastIndex = 0;
 
     for (int i = 1, size = myProduction.size() - 1; i < size; i++) {
       ProductionMarker item = myProduction.get(i);
@@ -1162,7 +1163,7 @@ public class PsiBuilderImpl extends UserDataHolderBase implements PsiBuilder {
       }
 
       int prevProductionLexIndex = myProduction.get(i - 1).myLexemeIndex;
-      int wsStartIndex = item.myLexemeIndex;
+      int wsStartIndex = Math.max(item.myLexemeIndex, lastIndex);
       while (wsStartIndex > prevProductionLexIndex && whitespaceOrComment(myLexTypes[wsStartIndex - 1])) wsStartIndex--;
       int wsEndIndex = item.myLexemeIndex;
       while (wsEndIndex < myLexemeCount && whitespaceOrComment(myLexTypes[wsEndIndex])) wsEndIndex++;
@@ -1173,6 +1174,11 @@ public class PsiBuilderImpl extends UserDataHolderBase implements PsiBuilder {
         boolean atEnd = wsStartIndex == 0 || wsEndIndex == myLexemeCount;
         item.myLexemeIndex = wsStartIndex + item.myEdgeTokenBinder.getEdgePosition(wsTokens, atEnd, tokenTextGetter);
       }
+      else if (item.myLexemeIndex < wsStartIndex) {
+        item.myLexemeIndex = wsStartIndex;
+      }
+
+      lastIndex = item.myLexemeIndex;
     }
   }
 
diff --git a/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java b/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java
index 5390ee8eb228..db833c2d8f3e 100644
--- a/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java
+++ b/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java
@@ -461,6 +461,27 @@ public class PsiBuilderQuickTest extends LightPlatformLangTestCase {
            "    PsiElement(OTHER)('}')\n");
   }
 
+  public void testEndMarkersOverlapping() {
+    doTest("a ",
+           new Parser() {
+             @Override
+             public void parse(PsiBuilder builder) {
+               PsiBuilder.Marker e1 = builder.mark();
+               PsiBuilder.Marker e2 = builder.mark();
+               builder.advanceLexer();
+               e2.done(OTHER);
+               e2.setCustomEdgeTokenBinders(null, WhitespacesBinders.GREEDY_RIGHT_BINDER);
+               e1.done(OTHER);
+               e1.setCustomEdgeTokenBinders(null, WhitespacesBinders.DEFAULT_RIGHT_BINDER);
+               assertTrue(builder.eof());
+             }
+           },
+           "Element(ROOT)\n" +
+           "  Element(OTHER)\n" +
+           "    Element(OTHER)\n" +
+           "      PsiElement(LETTER)('a')\n" +
+           "      PsiWhiteSpace(' ')\n");
+  }
 
   private interface Parser {
     void parse(PsiBuilder builder);