diff --git a/platform/diff-impl/src/com/intellij/diff/comparison/ByLine.java b/platform/diff-impl/src/com/intellij/diff/comparison/ByLine.java
index 1b93664453dd..ed57ad02c7b9 100644
--- a/platform/diff-impl/src/com/intellij/diff/comparison/ByLine.java
+++ b/platform/diff-impl/src/com/intellij/diff/comparison/ByLine.java
@@ -15,7 +15,7 @@
  */
 package com.intellij.diff.comparison;
 
-import com.intellij.diff.comparison.iterables.DiffIterableUtil.TrimChangeBuilder;
+import com.intellij.diff.comparison.iterables.DiffIterableUtil.*;
 import com.intellij.diff.comparison.iterables.FairDiffIterable;
 import com.intellij.diff.fragments.LineFragment;
 import com.intellij.diff.fragments.LineFragmentImpl;
@@ -38,8 +38,7 @@ import java.util.List;
 
 import static com.intellij.diff.comparison.TrimUtil.trimEnd;
 import static com.intellij.diff.comparison.TrimUtil.trimStart;
-import static com.intellij.diff.comparison.iterables.DiffIterableUtil.diff;
-import static com.intellij.diff.comparison.iterables.DiffIterableUtil.fair;
+import static com.intellij.diff.comparison.iterables.DiffIterableUtil.*;
 import static com.intellij.openapi.util.text.StringUtil.isWhiteSpace;
 
 public class ByLine {
@@ -55,6 +54,7 @@ public class ByLine {
 
     FairDiffIterable changes = compareSmart(lines1, lines2, indicator);
     changes = optimizeLineChunks(lines1, lines2, changes, indicator);
+    changes = expandRanges(lines1, lines2, changes, indicator);
     return convertIntoFragments(lines1, lines2, changes);
   }
 
@@ -141,7 +141,7 @@ public class ByLine {
      *   c. match equal lines using result of the previous step
      */
 
-    final TrimChangeBuilder builder = new TrimChangeBuilder(lines1, lines2);
+    final ExpandChangeBuilder builder = new ExpandChangeBuilder(lines1, lines2);
     new Object() {
       private CharSequence sample = null;
       private int last1 = -1;
@@ -367,6 +367,21 @@ public class ByLine {
     return Pair.create(bigLines, indexes);
   }
 
+  @NotNull
+  private static FairDiffIterable expandRanges(@NotNull List<Line> lines1,
+                                               @NotNull List<Line> lines2,
+                                               @NotNull FairDiffIterable iterable,
+                                               @NotNull ProgressIndicator indicator) {
+    List<Range> changes = new ArrayList<Range>();
+
+    for (Range ch : iterable.iterateChanges()) {
+      Range expanded = TrimUtil.expand(lines1, lines2, ch.start1, ch.start2, ch.end1, ch.end2);
+      if (!expanded.isEmpty()) changes.add(expanded);
+    }
+
+    return fair(create(changes, lines1.size(), lines2.size()));
+  }
+
   //
   // Lines
   //
diff --git a/platform/diff-impl/src/com/intellij/diff/comparison/iterables/DiffIterableUtil.java b/platform/diff-impl/src/com/intellij/diff/comparison/iterables/DiffIterableUtil.java
index d97c1dc195de..d7b8f097a92d 100644
--- a/platform/diff-impl/src/com/intellij/diff/comparison/iterables/DiffIterableUtil.java
+++ b/platform/diff-impl/src/com/intellij/diff/comparison/iterables/DiffIterableUtil.java
@@ -336,11 +336,11 @@ public class DiffIterableUtil {
     }
   }
 
-  public static class TrimChangeBuilder extends ChangeBuilder {
+  public static class ExpandChangeBuilder extends ChangeBuilder {
     @NotNull private final List<?> myObjects1;
     @NotNull private final List<?> myObjects2;
 
-    public TrimChangeBuilder(@NotNull List<?> objects1, @NotNull List<?> objects2) {
+    public ExpandChangeBuilder(@NotNull List<?> objects1, @NotNull List<?> objects2) {
       super(objects1.size(), objects2.size());
       myObjects1 = objects1;
       myObjects2 = objects2;
diff --git a/platform/diff-impl/tests/com/intellij/diff/comparison/LineComparisonUtilTest.kt b/platform/diff-impl/tests/com/intellij/diff/comparison/LineComparisonUtilTest.kt
index c9359c06816e..41cfa05b0dae 100644
--- a/platform/diff-impl/tests/com/intellij/diff/comparison/LineComparisonUtilTest.kt
+++ b/platform/diff-impl/tests/com/intellij/diff/comparison/LineComparisonUtilTest.kt
@@ -311,6 +311,14 @@ class LineComparisonUtilTest : ComparisonUtilTestBase() {
     }
   }
 
+  fun `test regression - can trim chunks after 'optimizeLineChunks'`() {
+    lines {
+      ("A=====_ B=====_ }_}_B=====_" - "A=====_ }_}_B=====_")
+      default(del(1, 1, 1))
+      testAll()
+    }
+  }
+
   fun `test bad cases caused by 'compareTwoStep' logic`() {
     lines {
       ("x_!" - "!_x_y")
@@ -339,14 +347,6 @@ class LineComparisonUtilTest : ComparisonUtilTestBase() {
   }
 
   fun `test bad cases caused by 'compareSmart' logic`() {
-    lines {
-      ("A=====_ B=====_ }_}_B=====_" - "A=====_ }_}_B=====_")
-      // TODO: ignore(del(1, 1, 1))
-      default(del(1, 1, 1))
-      ignore(mod(1, 1, 3, 2))
-      testAll()
-    }
-
     lines {
       ("A=====_ B=====_ }_}_B=====" - "A=====_ }_}_B=====")
       // TODO trim(del(1, 1, 1))