persistent rangemarker update for small documents

platform/core-impl/src/com/intellij/openapi/editor/impl/PersistentRangeMarker.java

@@ -69,19 +69,24 @@ class PersistentRangeMarker extends RangeMarkerImpl {
   private boolean translateViaDiff(final DocumentEventImpl event) {
     try {
       myStartLine = event.translateLineViaDiffStrict(myStartLine);
-      if (myStartLine < 0 || myStartLine >= getDocument().getLineCount()) {
+      DocumentEx document = getDocument();
+      if (myStartLine < 0 || myStartLine >= document.getLineCount()) {
         invalidate(event);
       }
       else {
-        setIntervalStart(getDocument().getLineStartOffset(myStartLine) + myStartColumn);
+        int start = document.getLineStartOffset(myStartLine) + myStartColumn;
+        if (start >= document.getTextLength()) return false;
+        setIntervalStart(start);
       }
 
       myEndLine = event.translateLineViaDiffStrict(myEndLine);
-      if (myEndLine < 0 || myEndLine >= getDocument().getLineCount()) {
+      if (myEndLine < 0 || myEndLine >= document.getLineCount()) {
         invalidate(event);
       }
       else {
-        setIntervalEnd(getDocument().getLineStartOffset(myEndLine) + myEndColumn);
+        int end = document.getLineStartOffset(myEndLine) + myEndColumn;
+        if (end > document.getTextLength()) return false;
+        setIntervalEnd(end);
       }
       return true;
     }

platform/platform-tests/testSrc/com/intellij/openapi/editor/RangeMarkerTest.java

@@ -1045,4 +1045,15 @@ public class RangeMarkerTest extends LightPlatformTestCase {
       EditorFactory.getInstance().releaseEditor(editor);
     }
   }
+  public void testPersistent() throws Exception {
+    String text = "xxx\nzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz";
+    Document document = EditorFactory.getInstance().createDocument(text);
+    int startOffset = text.indexOf('z');
+    int endOffset = text.lastIndexOf('z');
+    RangeMarker marker = document.createRangeMarker(startOffset, endOffset, true);
+
+    document.replaceString(startOffset+1, endOffset-1, "ccc");
+
+    assertTrue(marker.isValid());
+  }
 }