diff: update foldings in a single batch operation

This fixes completion popup blinking on typing
If we destroy and install foldings in separate operaions, caret's visual position jumps back and forth, triggering popup close

platform/diff-impl/src/com/intellij/diff/tools/simple/SimpleDiffViewer.java

@@ -99,6 +99,7 @@ public class SimpleDiffViewer extends TwosideTextDiffViewer {
   @CalledInAwt
   protected void onDispose() {
     destroyChangedBlocks();
+    myFoldingModel.destroy();
     super.onDispose();
   }
 
@@ -225,6 +226,7 @@ public class SimpleDiffViewer extends TwosideTextDiffViewer {
   private Runnable apply(@NotNull final CompareData data) {
     return () -> {
       myFoldingModel.updateContext(myRequest, getFoldingModelSettings());
+
       clearDiffPresentation();
 
       myIsContentsEqual = data.isContentsEqual();
@@ -253,6 +255,7 @@ public class SimpleDiffViewer extends TwosideTextDiffViewer {
   private Runnable applyNotification(@Nullable final JComponent notification) {
     return () -> {
       clearDiffPresentation();
+      myFoldingModel.destroy();
       if (notification != null) myPanel.addNotification(notification);
     };
   }
@@ -290,8 +293,6 @@ public class SimpleDiffViewer extends TwosideTextDiffViewer {
     }
     myInvalidDiffChanges.clear();
 
-    myFoldingModel.destroy();
-
     myContentPanel.repaintDivider();
     myStatusPanel.update();
   }

platform/diff-impl/src/com/intellij/diff/tools/simple/ThreesideTextDiffViewerEx.java

@@ -88,6 +88,7 @@ public abstract class ThreesideTextDiffViewerEx extends ThreesideTextDiffViewer
   @CalledInAwt
   protected void onDispose() {
     destroyChangedBlocks();
+    myFoldingModel.destroy();
     super.onDispose();
   }
 
@@ -119,6 +120,7 @@ public abstract class ThreesideTextDiffViewerEx extends ThreesideTextDiffViewer
   protected Runnable applyNotification(@Nullable final JComponent notification) {
     return () -> {
       clearDiffPresentation();
+      myFoldingModel.destroy();
       if (notification != null) myPanel.addNotification(notification);
     };
   }
@@ -135,7 +137,6 @@ public abstract class ThreesideTextDiffViewerEx extends ThreesideTextDiffViewer
 
   @CalledInAwt
   protected void destroyChangedBlocks() {
-    myFoldingModel.destroy();
   }
 
   //

platform/diff-impl/src/com/intellij/diff/tools/util/FoldingModelSupport.java

@@ -100,12 +100,21 @@ public class FoldingModelSupport {
                          @NotNull final Settings settings) {
     ApplicationManager.getApplication().assertIsDispatchThread();
 
-    if (changedLines == null) return;
-    if (settings.range == -1) return;
+    for (FoldedBlock folding : getFoldedBlocks()) {
+      folding.destroyHighlighter();
+    }
 
     runBatchOperation(() -> {
-      FoldingBuilder builder = new FoldingBuilder(context, settings);
-      builder.build(changedLines);
+      for (FoldedBlock folding : getFoldedBlocks()) {
+        folding.destroyFolding();
+      }
+      myFoldings.clear();
+
+
+      if (changedLines != null && settings.range != -1) {
+        FoldingBuilder builder = new FoldingBuilder(context, settings);
+        builder.build(changedLines);
+      }
     });
 
     updateLineNumbers(true);
@@ -244,23 +253,15 @@ public class FoldingModelSupport {
   }
 
   public void destroy() {
-    for (int i = 0; i < myCount; i++) {
-      destroyFoldings(i);
-    }
-
     for (FoldedBlock folding : getFoldedBlocks()) {
       folding.destroyHighlighter();
     }
-    myFoldings.clear();
-  }
 
-  private void destroyFoldings(final int index) {
-    final FoldingModelEx model = myEditors[index].getFoldingModel();
-    model.runBatchFoldingOperation(() -> {
+    runBatchOperation(() -> {
       for (FoldedBlock folding : getFoldedBlocks()) {
-        FoldRegion region = folding.getRegion(index);
-        if (region != null) model.removeFoldRegion(region);
+        folding.destroyFolding();
       }
+      myFoldings.clear();
     });
   }
 
@@ -615,6 +616,13 @@ public class FoldingModelSupport {
       }
     }
 
+    public void destroyFolding() {
+      for (int i = 0; i < myCount; i++) {
+        FoldRegion region = myRegions[i];
+        if (region != null) myEditors[i].getFoldingModel().removeFoldRegion(region);
+      }
+    }
+
     public void destroyHighlighter() {
       for (RangeHighlighter highlighter : myHighlighters) {
         highlighter.dispose();