1 files changed, 18 insertions, 6 deletions

diff --git a/platform/platform-impl/src/com/intellij/openapi/diff/impl/processing/TextCompareProcessor.java b/platform/platform-impl/src/com/intellij/openapi/diff/impl/processing/TextCompareProcessor.java
index b2da49ef2008..e527964a5c0d 100644
--- a/platform/platform-impl/src/com/intellij/openapi/diff/impl/processing/TextCompareProcessor.java
+++ b/platform/platform-impl/src/com/intellij/openapi/diff/impl/processing/TextCompareProcessor.java
@@ -23,8 +23,10 @@ import com.intellij.openapi.diff.impl.fragments.LineFragment;
 import com.intellij.openapi.diff.impl.highlighting.FragmentSide;
 import com.intellij.openapi.diff.impl.highlighting.LineBlockDivider;
 import com.intellij.openapi.diff.impl.highlighting.Util;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.util.diff.FilesTooBigForDiffException;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 
@@ -50,7 +52,9 @@ public class TextCompareProcessor {
     this(comparisonPolicy, DiffPolicy.LINES_WO_FORMATTING);
   }
 
-  public ArrayList<LineFragment> process(String text1, String text2) throws FilesTooBigForDiffException {
+  public ArrayList<LineFragment> process(@Nullable String text1, @Nullable String text2) throws FilesTooBigForDiffException {
+    text1 = StringUtil.notNullize(text1);
+    text2 = StringUtil.notNullize(text2);
     if (text1.isEmpty() || text2.isEmpty()) {
       return new DummyDiffFragmentsProcessor().process(text1, text2);
     }
@@ -59,14 +63,22 @@ public class TextCompareProcessor {
     DiffFragment[] step1lineFragments = new DiffCorrection.TrueLineBlocks(myComparisonPolicy).correctAndNormalize(woFormattingBlocks);
     ArrayList<LineFragment> lineBlocks = new DiffFragmentsProcessor().process(step1lineFragments);
 
+    int badLinesCount = 0;
     if (mySearchForSubFragments) {
       for (LineFragment lineBlock : lineBlocks) {
         if (lineBlock.isOneSide() || lineBlock.isEqual()) continue;
-        String subText1 = lineBlock.getText(text1, FragmentSide.SIDE1);
-        String subText2 = lineBlock.getText(text2, FragmentSide.SIDE2);
-        ArrayList<LineFragment> subFragments = findSubFragments(subText1, subText2);
-        lineBlock.setChildren(new ArrayList<Fragment>(subFragments));
-        lineBlock.adjustTypeFromChildrenTypes();
+        try {
+          String subText1 = lineBlock.getText(text1, FragmentSide.SIDE1);
+          String subText2 = lineBlock.getText(text2, FragmentSide.SIDE2);
+          ArrayList<LineFragment> subFragments = findSubFragments(subText1, subText2);
+          lineBlock.setChildren(new ArrayList<Fragment>(subFragments));
+          lineBlock.adjustTypeFromChildrenTypes();
+        }
+        catch (FilesTooBigForDiffException ignore) {
+          // If we can't by-word compare two lines - this is not a reason to break entire diff.
+          badLinesCount++;
+          if (badLinesCount > FilesTooBigForDiffException.MAX_BAD_LINES) break;
+        }
       }
     }
     return lineBlocks;