preserve consistency of EditorSizeManager state when editor is modified while it's hidden

platform/platform-impl/src/com/intellij/openapi/editor/impl/SoftWrapModelImpl.java

@@ -754,6 +754,10 @@ public class SoftWrapModelImpl implements SoftWrapModelEx, PrioritizedInternalDo
     return dumpState();
   }
 
+  public boolean isDirty() {
+    return myDirty;
+  }
+  
   /**
    * Defines generic interface for the command that may be proceeded in both <code>'soft wraps aware'</code> and
    * <code>'soft wraps unaware'</code> modes.

platform/platform-impl/src/com/intellij/openapi/editor/impl/view/EditorSizeManager.java

@@ -70,6 +70,10 @@ class EditorSizeManager implements PrioritizedDocumentListener, Disposable, Fold
   private int myFoldingChangeStartOffset = Integer.MAX_VALUE;
   private int myFoldingChangeEndOffset = Integer.MIN_VALUE;
   
+  private boolean myDirty; // true if we cannot calculate preferred size now because soft wrap model was invalidated after editor 
+                           // became hidden. myLineWidths contents is irrelevant in such a state. Previously calculated preferred size
+                           // is kept until soft wraps will be recalculated and size calculations will become possible
+  
   private final List<TextRange> myDeferredRanges = new ArrayList<TextRange>();
   
   private final SoftWrapAwareDocumentParsingListenerAdapter mySoftWrapChangeListener = new SoftWrapAwareDocumentParsingListenerAdapter() {
@@ -179,6 +183,7 @@ class EditorSizeManager implements PrioritizedDocumentListener, Disposable, Fold
   private int getPreferredWidth() {
     if (myWidthInPixels < 0) {
       assert !myDocument.isInBulkUpdate();
+      assert !myDirty;
       myWidthInPixels = calculatePreferredWidth();
     }
     validateMaxLineWithExtension();
@@ -273,6 +278,11 @@ class EditorSizeManager implements PrioritizedDocumentListener, Disposable, Fold
   }
   
   private void doInvalidateRange(int startOffset, int endOffset) {
+    if (myDirty) return;
+    if (myEditor.getSoftWrapModel().isDirty()) {
+      myDirty = true;
+      return;
+    }
     myWidthInPixels = -1;
     int startVisualLine = myView.offsetToVisualLine(startOffset, false);
     int endVisualLine = myView.offsetToVisualLine(endOffset, true);
@@ -309,6 +319,11 @@ class EditorSizeManager implements PrioritizedDocumentListener, Disposable, Fold
   }
 
   private void onTextLayoutPerformed(int startOffset, int endOffset) {
+    if (myDirty) return;
+    if (myEditor.getSoftWrapModel().isDirty()) {
+      myDirty = true;
+      return;
+    }
     boolean purePaintingMode = myEditor.isPurePaintingMode();
     boolean foldingEnabled = myEditor.getFoldingModel().isFoldingEnabled();
     myEditor.setPurePaintingMode(false);