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 ee6d440cc270..5cee140c10f6 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
@@ -42,7 +42,7 @@ public class DiffIterableUtil {
    * Compare two integer arrays
    */
   @NotNull
-  public static <T> FairDiffIterable diff(@NotNull int[] data1, @NotNull int[] data2, @NotNull ProgressIndicator indicator) {
+  public static FairDiffIterable diff(@NotNull int[] data1, @NotNull int[] data2, @NotNull ProgressIndicator indicator) {
     indicator.checkCanceled();
 
     try {
diff --git a/platform/diff-impl/src/com/intellij/diff/merge/TextMergeViewer.java b/platform/diff-impl/src/com/intellij/diff/merge/TextMergeViewer.java
index 0c7e0f59ab30..2253abf942b1 100644
--- a/platform/diff-impl/src/com/intellij/diff/merge/TextMergeViewer.java
+++ b/platform/diff-impl/src/com/intellij/diff/merge/TextMergeViewer.java
@@ -1421,7 +1421,7 @@ public class TextMergeViewer implements MergeTool.MergeViewer {
   }
 
   private static class MyUndoableAction extends BasicUndoableAction {
-    private final WeakReference<TextMergeViewer> myViewerRef;
+    @NotNull private final WeakReference<TextMergeViewer> myViewerRef;
     @NotNull private final List<TextMergeChange.State> myStates;
     private final boolean myUndo;
 
diff --git a/platform/diff-impl/src/com/intellij/diff/tools/binary/OnesideBinaryDiffViewer.java b/platform/diff-impl/src/com/intellij/diff/tools/binary/OnesideBinaryDiffViewer.java
index 62ae60008de8..2023ca0bbe12 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/binary/OnesideBinaryDiffViewer.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/binary/OnesideBinaryDiffViewer.java
@@ -39,7 +39,7 @@ import static java.util.Collections.singletonList;
 public class OnesideBinaryDiffViewer extends OnesideDiffViewer<BinaryEditorHolder> {
   public static final Logger LOG = Logger.getInstance(OnesideBinaryDiffViewer.class);
 
-  private final TransferableFileEditorStateSupport myTransferableStateSupport;
+  @NotNull private final TransferableFileEditorStateSupport myTransferableStateSupport;
 
   public OnesideBinaryDiffViewer(@NotNull DiffContext context, @NotNull DiffRequest request) {
     super(context, (ContentDiffRequest)request, BinaryEditorHolder.BinaryEditorHolderFactory.INSTANCE);
diff --git a/platform/diff-impl/src/com/intellij/diff/tools/binary/ThreesideBinaryDiffViewer.java b/platform/diff-impl/src/com/intellij/diff/tools/binary/ThreesideBinaryDiffViewer.java
index c9355143d80b..110787a4147a 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/binary/ThreesideBinaryDiffViewer.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/binary/ThreesideBinaryDiffViewer.java
@@ -32,7 +32,7 @@ import java.util.List;
 import static com.intellij.diff.util.DiffUtil.getDiffSettings;
 
 public class ThreesideBinaryDiffViewer extends ThreesideDiffViewer<BinaryEditorHolder> {
-  private final TransferableFileEditorStateSupport myTransferableStateSupport;
+  @NotNull private final TransferableFileEditorStateSupport myTransferableStateSupport;
 
   public ThreesideBinaryDiffViewer(@NotNull DiffContext context, @NotNull DiffRequest request) {
     super(context, (ContentDiffRequest)request, BinaryEditorHolder.BinaryEditorHolderFactory.INSTANCE);
diff --git a/platform/diff-impl/src/com/intellij/diff/tools/binary/TwosideBinaryDiffViewer.java b/platform/diff-impl/src/com/intellij/diff/tools/binary/TwosideBinaryDiffViewer.java
index 2b9236e2e92a..d717d4e125b3 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/binary/TwosideBinaryDiffViewer.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/binary/TwosideBinaryDiffViewer.java
@@ -57,7 +57,7 @@ import static com.intellij.diff.util.DiffUtil.getDiffSettings;
 public class TwosideBinaryDiffViewer extends TwosideDiffViewer<BinaryEditorHolder> {
   public static final Logger LOG = Logger.getInstance(TwosideBinaryDiffViewer.class);
 
-  private final TransferableFileEditorStateSupport myTransferableStateSupport;
+  @NotNull private final TransferableFileEditorStateSupport myTransferableStateSupport;
   @NotNull private final StatusPanel myStatusPanel;
 
   public TwosideBinaryDiffViewer(@NotNull DiffContext context, @NotNull DiffRequest request) {
diff --git a/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java b/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java
index e1bd465f9c83..ef7f335aec4c 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/external/ExternalDiffToolUtil.java
@@ -430,7 +430,7 @@ public class ExternalDiffToolUtil {
 
     @Override
     public void cleanup() {
-      myLocalFile.delete();
+      FileUtil.delete(myLocalFile);
     }
   }
 }
diff --git a/platform/diff-impl/src/com/intellij/diff/tools/simple/SimpleDiffChange.java b/platform/diff-impl/src/com/intellij/diff/tools/simple/SimpleDiffChange.java
index 0a4edd17519e..dfd771c32a33 100644
--- a/platform/diff-impl/src/com/intellij/diff/tools/simple/SimpleDiffChange.java
+++ b/platform/diff-impl/src/com/intellij/diff/tools/simple/SimpleDiffChange.java
@@ -239,20 +239,11 @@ public class SimpleDiffChange {
     public GutterIconRenderer createRenderer() {
       myCtrlPressed = myViewer.getModifierProvider().isCtrlPressed();
 
-      boolean isEditable = DiffUtil.isEditable(myViewer.getEditor(mySide));
       boolean isOtherEditable = DiffUtil.isEditable(myViewer.getEditor(mySide.other()));
       boolean isAppendable = myFragment.getStartLine1() != myFragment.getEndLine1() &&
                              myFragment.getStartLine2() != myFragment.getEndLine2();
 
-      if (isOtherEditable && isEditable) {
-        if (myCtrlPressed && isAppendable) {
-          return createAppendRenderer(mySide);
-        }
-        else {
-          return createApplyRenderer(mySide);
-        }
-      }
-      else if (isOtherEditable) {
+      if (isOtherEditable) {
         if (myCtrlPressed && isAppendable) {
           return createAppendRenderer(mySide);
         }
diff --git a/platform/util/src/com/intellij/util/diff/Diff.java b/platform/util/src/com/intellij/util/diff/Diff.java
index 5559266b252c..721771cb8f07 100644
--- a/platform/util/src/com/intellij/util/diff/Diff.java
+++ b/platform/util/src/com/intellij/util/diff/Diff.java
@@ -80,7 +80,7 @@ public class Diff {
   }
 
   @Nullable
-  public static <T> Change buildChanges(@NotNull int[] array1, @NotNull int[] array2) throws FilesTooBigForDiffException {
+  public static Change buildChanges(@NotNull int[] array1, @NotNull int[] array2) throws FilesTooBigForDiffException {
     final int startShift = getStartShift(array1, array2);
     final int endCut = getEndCut(array1, array2, startShift);
 
@@ -140,28 +140,28 @@ public class Diff {
     return builder.getFirstChange();
   }
 
-  private static <T> int getStartShift(final T[] o1, final T[] o2) {
+  private static <T> int getStartShift(@NotNull final T[] o1, @NotNull final T[] o2) {
     final int size = Math.min(o1.length, o2.length);
     int idx = 0;
     for (int i = 0; i < size; i++) {
-      if (! o1[i].equals(o2[i])) break;
-      ++ idx;
+      if (!o1[i].equals(o2[i])) break;
+      ++idx;
     }
     return idx;
   }
 
-  private static <T> int getEndCut(final T[] o1, final T[] o2, final int startShift) {
+  private static <T> int getEndCut(@NotNull final T[] o1, @NotNull final T[] o2, int startShift) {
     final int size = Math.min(o1.length, o2.length) - startShift;
     int idx = 0;
 
     for (int i = 0; i < size; i++) {
-      if (! o1[o1.length - i - 1].equals(o2[o2.length - i - 1])) break;
-      ++ idx;
+      if (!o1[o1.length - i - 1].equals(o2[o2.length - i - 1])) break;
+      ++idx;
     }
     return idx;
   }
 
-  private static int getStartShift(final int[] o1, final int[] o2) {
+  private static int getStartShift(@NotNull final int[] o1, @NotNull final int[] o2) {
     final int size = Math.min(o1.length, o2.length);
     int idx = 0;
     for (int i = 0; i < size; i++) {
@@ -171,7 +171,7 @@ public class Diff {
     return idx;
   }
 
-  private static int getEndCut(final int[] o1, final int[] o2, final int startShift) {
+  private static int getEndCut(@NotNull final int[] o1, @NotNull final int[] o2, final int startShift) {
     final int size = Math.min(o1.length, o2.length) - startShift;
     int idx = 0;