Don't try to Place() invisible operators. b=420420 r+sr=roc a=beltzner

layout/mathml/base/src/nsMathMLmoFrame.cpp

@@ -758,12 +758,15 @@ nsMathMLmoFrame::Stretch(nsIRenderingContext& aRenderingContext,
     }
   }
 
-  // Place our children using the default method
-  // This will allow our child text frame to get its DidReflow()
-  nsresult rv = Place(aRenderingContext, PR_TRUE, aDesiredStretchSize);
-  if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
-    // Make sure the child frames get their DidReflow() calls.
-    DidReflowChildren(mFrames.FirstChild());
+  // Child frames of invisble operators are not reflowed
+  if (!NS_MATHML_OPERATOR_IS_INVISIBLE(mFlags)) {
+    // Place our children using the default method
+    // This will allow our child text frame to get its DidReflow()
+    nsresult rv = Place(aRenderingContext, PR_TRUE, aDesiredStretchSize);
+    if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
+      // Make sure the child frames get their DidReflow() calls.
+      DidReflowChildren(mFrames.FirstChild());
+    }
   }
 
   if (useMathMLChar) {