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 3338241e705a..c68f20e07082 100644
--- a/platform/core-impl/src/com/intellij/lang/impl/PsiBuilderImpl.java
+++ b/platform/core-impl/src/com/intellij/lang/impl/PsiBuilderImpl.java
@@ -1152,8 +1152,8 @@ public class PsiBuilderImpl extends UserDataHolderBase implements PsiBuilder {
   }
 
   private void balanceWhiteSpaces() {
-    RelativeTokenTypesView wsTokens = null;
-    RelativeTokenTextView tokenTextGetter = null;
+    RelativeTokenTypesView wsTokens = new RelativeTokenTypesView();
+    RelativeTokenTextView tokenTextGetter = new RelativeTokenTextView();
 
     for (int i = 1, size = myProduction.size() - 1; i < size; i++) {
       final ProductionMarker item = myProduction.get(i);
@@ -1162,54 +1162,50 @@ public class PsiBuilderImpl extends UserDataHolderBase implements PsiBuilder {
         LOG.error(UNBALANCED_MESSAGE);
       }
 
-      final int prevProductionLexIndex = myProduction.get(i - 1).myLexemeIndex;
-      int idx = item.myLexemeIndex;
-      while (idx > prevProductionLexIndex && whitespaceOrComment(myLexTypes[idx - 1])) idx--;
-      final int wsStartIndex = idx;
-
+      int prevProductionLexIndex = myProduction.get(i - 1).myLexemeIndex;
+      int wsStartIndex = item.myLexemeIndex;
+      while (wsStartIndex > prevProductionLexIndex && whitespaceOrComment(myLexTypes[wsStartIndex - 1])) wsStartIndex--;
       int wsEndIndex = item.myLexemeIndex;
       while (wsEndIndex < myLexemeCount && whitespaceOrComment(myLexTypes[wsEndIndex])) wsEndIndex++;
 
-      if (wsTokens == null) wsTokens = new RelativeTokenTypesView();
       wsTokens.configure(wsStartIndex, wsEndIndex);
-      final boolean atEnd = wsStartIndex == 0 || wsEndIndex == myLexemeCount;
-      if (tokenTextGetter == null) tokenTextGetter = new RelativeTokenTextView();
       tokenTextGetter.configure(wsStartIndex);
+      boolean atEnd = wsStartIndex == 0 || wsEndIndex == myLexemeCount;
 
       item.myLexemeIndex = wsStartIndex + item.myEdgeTokenBinder.getEdgePosition(wsTokens, atEnd, tokenTextGetter);
     }
   }
 
   private final class RelativeTokenTypesView extends AbstractList<IElementType> {
-    private int start;
-    private int size;
+    private int myStart;
+    private int mySize;
 
-    private void configure(int _start, int _end) {
-      size = _end - _start;
-      start = _start;
+    private void configure(int start, int end) {
+      myStart = start;
+      mySize = end - start;
     }
 
     @Override
-    public IElementType get(final int index) {
-      return myLexTypes[start + index];
+    public IElementType get(int index) {
+      return myLexTypes[myStart + index];
     }
 
     @Override
     public int size() {
-      return size;
+      return mySize;
     }
   }
 
   private final class RelativeTokenTextView implements WhitespacesAndCommentsBinder.TokenTextGetter {
-    private int start;
+    private int myStart;
 
-    private void configure(int _start) {
-      start = _start;
+    private void configure(int start) {
+      myStart = start;
     }
 
     @Override
-    public CharSequence get(final int i) {
-      return myText.subSequence(myLexStarts[start + i], myLexStarts[start + i + 1]);
+    public CharSequence get(int i) {
+      return myText.subSequence(myLexStarts[myStart + i], myLexStarts[myStart + i + 1]);
     }
   }
 
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/text/DiffLog.java b/platform/core-impl/src/com/intellij/psi/impl/source/text/DiffLog.java
index d41138043e95..386fb2dea0e9 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/text/DiffLog.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/text/DiffLog.java
@@ -39,8 +39,7 @@ import java.util.List;
  * User: cdr
  */
 public class DiffLog implements DiffTreeChangeBuilder<ASTNode,ASTNode> {
-  public DiffLog() {
-  }
+  public DiffLog() { }
 
   private abstract static class LogEntry {
     protected LogEntry() {
@@ -58,7 +57,6 @@ public class DiffLog implements DiffTreeChangeBuilder<ASTNode,ASTNode> {
       entry.doActualPsiChange(file, astDiffBuilder);
     }
     file.subtreeChanged();
-
     return astDiffBuilder.getEvent();
   }
 
@@ -83,7 +81,6 @@ public class DiffLog implements DiffTreeChangeBuilder<ASTNode,ASTNode> {
   @Override
   public void nodeDeleted(@NotNull ASTNode oldParent, @NotNull ASTNode oldNode) {
     myEntries.add(new DeleteEntry(oldParent, oldNode));
-
   }
 
   @Override
@@ -126,14 +123,12 @@ public class DiffLog implements DiffTreeChangeBuilder<ASTNode,ASTNode> {
 
       astDiffBuilder.nodeReplaced(oldNode, newNode);
 
-      /////////////////
       ((TreeElement)newNode).clearCaches();
       if (!(newNode instanceof FileElement)) {
         ((CompositeElement)newNode.getTreeParent()).subtreeChanged();
       }
 
       DebugUtil.checkTreeStructure(parent);
-
     }
   }
 
@@ -168,7 +163,6 @@ public class DiffLog implements DiffTreeChangeBuilder<ASTNode,ASTNode> {
       ((CompositeElement)parent).subtreeChanged();
 
       DebugUtil.checkTreeStructure(parent);
-
     }
   }
 
@@ -222,7 +216,6 @@ public class DiffLog implements DiffTreeChangeBuilder<ASTNode,ASTNode> {
 
       DebugUtil.checkTreeStructure(myOldParent);
     }
-
   }
 
   private static PsiElement getPsi(ASTNode node, PsiFile file) {
diff --git a/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java b/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java
index 5a47fdf4c5f3..cb83db5711f9 100644
--- a/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java
+++ b/platform/platform-tests/testSrc/com/intellij/lang/PsiBuilderQuickTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2014 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.
@@ -18,16 +18,14 @@ package com.intellij.lang;
 import com.intellij.lang.impl.PsiBuilderImpl;
 import com.intellij.lexer.Lexer;
 import com.intellij.lexer.LexerBase;
+import com.intellij.openapi.fileTypes.PlainTextParserDefinition;
 import com.intellij.openapi.project.Project;
-import com.intellij.psi.FileViewProvider;
-import com.intellij.psi.PsiElement;
-import com.intellij.psi.PsiFile;
 import com.intellij.psi.TokenType;
 import com.intellij.psi.impl.DebugUtil;
 import com.intellij.psi.impl.source.tree.ASTStructure;
 import com.intellij.psi.tree.*;
-import com.intellij.testFramework.LightPlatformTestCase;
-import com.intellij.testFramework.PlatformTestCase;
+import com.intellij.testFramework.LightPlatformLangTestCase;
+import com.intellij.testFramework.PlatformTestUtil;
 import com.intellij.util.ThreeState;
 import com.intellij.util.diff.DiffTree;
 import com.intellij.util.diff.DiffTreeChangeBuilder;
@@ -36,12 +34,9 @@ import com.intellij.util.diff.ShallowNodeComparator;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 
-import java.io.IOException;
-import java.io.OutputStream;
-import java.io.PrintStream;
 import java.util.List;
 
-public class PsiBuilderQuickTest extends LightPlatformTestCase {
+public class PsiBuilderQuickTest extends LightPlatformLangTestCase {
   private static final IFileElementType ROOT = new IFileElementType("ROOT", Language.ANY);
 
   private static final IElementType LETTER = new IElementType("LETTER", Language.ANY);
@@ -57,11 +52,6 @@ public class PsiBuilderQuickTest extends LightPlatformTestCase {
   private static final TokenSet WHITESPACE_SET = TokenSet.create(TokenType.WHITE_SPACE);
   private static final TokenSet COMMENT_SET = TokenSet.create(COMMENT);
 
-  @SuppressWarnings("JUnitTestCaseWithNonTrivialConstructors")
-  public PsiBuilderQuickTest() {
-    PlatformTestCase.initPlatformLangPrefix();
-  }
-
   public void testPlain() {
     doTest("a<<b",
            new Parser() {
@@ -478,25 +468,14 @@ public class PsiBuilderQuickTest extends LightPlatformTestCase {
            "    PsiElement(OTHER)('}')\n");
   }
 
-  @SuppressWarnings("ConstantConditions")
   private static PsiBuilderImpl createBuilder(CharSequence text) {
-    ParserDefinition parserDefinition = new ParserDefinition() {
+    ParserDefinition parserDefinition = new PlainTextParserDefinition() {
       @NotNull
       @Override
       public Lexer createLexer(Project project) {
         return new MyTestLexer();
       }
 
-      @Override
-      public PsiParser createParser(Project project) {
-        return null;
-      }
-
-      @Override
-      public IFileElementType getFileNodeType() {
-        return null;
-      }
-
       @NotNull
       @Override
       public TokenSet getWhitespaceTokens() {
@@ -508,28 +487,6 @@ public class PsiBuilderQuickTest extends LightPlatformTestCase {
       public TokenSet getCommentTokens() {
         return COMMENT_SET;
       }
-
-      @NotNull
-      @Override
-      public TokenSet getStringLiteralElements() {
-        return null;
-      }
-
-      @NotNull
-      @Override
-      public PsiElement createElement(ASTNode node) {
-        return null;
-      }
-
-      @Override
-      public PsiFile createFile(FileViewProvider viewProvider) {
-        return null;
-      }
-
-      @Override
-      public SpaceRequirements spaceExistanceTypeBetweenTokens(ASTNode left, ASTNode right) {
-        return null;
-      }
     };
     return new PsiBuilderImpl(getProject(), null, parserDefinition, parserDefinition.createLexer(getProject()), null, text, null, null);
   }
@@ -594,75 +551,21 @@ public class PsiBuilderQuickTest extends LightPlatformTestCase {
   }
 
   private static void doFailTest(@NonNls final String text, final Parser parser, @NonNls final String expected) {
-    final PrintStream std = System.err;
-    //noinspection IOResourceOpenedButNotSafelyClosed
-    System.setErr(new PrintStream(new NullStream()));
-    try {
-      try {
-        ParserDefinition parserDefinition = new ParserDefinition() {
-          @NotNull
-          @Override
-          public Lexer createLexer(Project project) {
-            return null;
-          }
-
-          @Override
-          public PsiParser createParser(Project project) {
-            return null;
-          }
-
-          @Override
-          public IFileElementType getFileNodeType() {
-            return null;
-          }
-
-          @NotNull
-          @Override
-          public TokenSet getWhitespaceTokens() {
-            return TokenSet.EMPTY;
-          }
-
-          @NotNull
-          @Override
-          public TokenSet getCommentTokens() {
-            return TokenSet.EMPTY;
-          }
-
-          @NotNull
-          @Override
-          public TokenSet getStringLiteralElements() {
-            return null;
-          }
-
-          @NotNull
-          @Override
-          public PsiElement createElement(ASTNode node) {
-            return null;
-          }
-
-          @Override
-          public PsiFile createFile(FileViewProvider viewProvider) {
-            return null;
-          }
-
-          @Override
-          public SpaceRequirements spaceExistanceTypeBetweenTokens(ASTNode left, ASTNode right) {
-            return null;
-          }
-        };
-        final PsiBuilder builder = PsiBuilderFactory.getInstance().createBuilder(parserDefinition, new MyTestLexer(),text);
-        builder.setDebugMode(true);
-        parser.parse(builder);
-        builder.getLightTree();
-        fail("should fail");
+    PlatformTestUtil.withStdErrSuppressed(new Runnable() {
+      @Override
+      public void run() {
+        try {
+          PsiBuilder builder = PsiBuilderFactory.getInstance().createBuilder(new PlainTextParserDefinition(), new MyTestLexer(), text);
+          builder.setDebugMode(true);
+          parser.parse(builder);
+          builder.getLightTree();
+          fail("should fail");
+        }
+        catch (AssertionError e) {
+          assertEquals(expected, e.getMessage());
+        }
       }
-      catch (AssertionError e) {
-        assertEquals(expected, e.getMessage());
-      }
-    }
-    finally {
-      System.setErr(std);
-    }
+    });
   }
 
   private static class MyTestLexer extends LexerBase {
@@ -719,11 +622,6 @@ public class PsiBuilderQuickTest extends LightPlatformTestCase {
     }
   }
 
-  private static class NullStream extends OutputStream {
-    @Override
-    public void write(final int b) throws IOException { }
-  }
-
   private static class MyChameleon1Type extends MyLazyElementType {
     private final IElementType myCHAMELEON_2;
 
diff --git a/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java b/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java
index 5a4aca43a265..307fb65e5ef1 100644
--- a/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java
+++ b/platform/testFramework/src/com/intellij/testFramework/PlatformTestUtil.java
@@ -63,9 +63,7 @@ import javax.swing.tree.DefaultMutableTreeNode;
 import javax.swing.tree.TreePath;
 import java.awt.*;
 import java.awt.event.InvocationEvent;
-import java.io.File;
-import java.io.IOException;
-import java.io.StringWriter;
+import java.io.*;
 import java.lang.ref.SoftReference;
 import java.nio.charset.Charset;
 import java.text.DecimalFormat;
@@ -826,4 +824,21 @@ public class PlatformTestUtil {
     ReflectionUtil.resetField(Charset.class, Charset.class, "defaultCharset");
     System.setProperty("file.encoding", encoding);
   }
+
+  public static void withStdErrSuppressed(@NotNull Runnable r) {
+    PrintStream std = System.err;
+    System.setErr(new PrintStream(NULL));
+    try {
+      r.run();
+    }
+    finally {
+      System.setErr(std);
+    }
+  }
+
+  @SuppressWarnings("IOResourceOpenedButNotSafelyClosed")
+  private static final OutputStream NULL = new OutputStream() {
+    @Override
+    public void write(int b) throws IOException { }
+  };
 }
diff --git a/platform/util/src/com/intellij/util/diff/DiffTree.java b/platform/util/src/com/intellij/util/diff/DiffTree.java
index 0bab60dc87da..680b15b7d1de 100644
--- a/platform/util/src/com/intellij/util/diff/DiffTree.java
+++ b/platform/util/src/com/intellij/util/diff/DiffTree.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2014 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.
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package com.intellij.util.diff;
 
 import com.intellij.openapi.util.Ref;
@@ -39,7 +38,6 @@ public class DiffTree<OT, NT> {
                    final FlyweightCapableTreeStructure<NT> newTree,
                    final ShallowNodeComparator<OT, NT> comparator,
                    final DiffTreeChangeBuilder<OT, NT> consumer) {
-
     myOldTree = oldTree;
     myNewTree = newTree;
     myComparator = comparator;
@@ -53,7 +51,7 @@ public class DiffTree<OT, NT> {
     new DiffTree<OT, NT>(oldTree, newTree, comparator, consumer).build(oldTree.getRoot(), newTree.getRoot(), 0);
   }
 
-  private static enum CompareResult {
+  private enum CompareResult {
     EQUAL, // 100% equal
     DRILL_DOWN_NEEDED, // element types are equal, but elements are composite
     TYPE_ONLY, // only element types are equal
@@ -146,6 +144,7 @@ public class DiffTree<OT, NT> {
         newIndex++;
         continue;
       }
+
       CompareResult c12 = looksEqual(comparator, oldChild1, newChild2);
       if (c12 == CompareResult.EQUAL || c12 == CompareResult.DRILL_DOWN_NEEDED || c12 == CompareResult.TYPE_ONLY) {
         myConsumer.nodeInserted(oldNode, newChild1, newIndex);
@@ -170,6 +169,7 @@ public class DiffTree<OT, NT> {
         oldIndex++;
         continue;
       }
+
       myConsumer.nodeReplaced(oldChild1, newChild1);
       oldIndex++;
       newIndex++;