Bug 557478 - Defer mfrac operator spacing to outermost embellished operator. r=fredw

layout/mathml/nsMathMLmfracFrame.cpp

@@ -222,8 +222,12 @@ nsMathMLmfracFrame::PlaceInternal(nsRenderingContext& aRenderingContext,
   GetRuleThickness(aRenderingContext, fm, defaultRuleThickness);
   GetAxisHeight(aRenderingContext, fm, axisHeight);
 
-  nsEmbellishData coreData;
-  GetEmbellishDataFrom(mEmbellishData.coreFrame, coreData);
+  bool outermostEmbellished = false;
+  if (mEmbellishData.coreFrame) {
+    nsEmbellishData parentData;
+    GetEmbellishDataFrom(mParent, parentData);
+    outermostEmbellished = parentData.coreFrame != mEmbellishData.coreFrame;
+  }
 
   // see if the linethickness attribute is there 
   nsAutoString value;
@@ -237,16 +241,22 @@ nsMathMLmfracFrame::PlaceInternal(nsRenderingContext& aRenderingContext,
 
   if (!mIsBevelled) {
     mLineRect.height = mLineThickness;
-    
-    // by default, leave at least one-pixel padding at either end, or use
-    // lspace & rspace that may come from <mo> if we are an embellished
-    // container (we fetch values from the core since they may use units that
-    // depend on style data, and style changes could have occurred in the
-    // core since our last visit there)
-    nscoord leftSpace = std::max(onePixel, StyleVisibility()->mDirection ?
-                               coreData.trailingSpace : coreData.leadingSpace);
-    nscoord rightSpace = std::max(onePixel, StyleVisibility()->mDirection ?
-                                coreData.leadingSpace : coreData.trailingSpace);
+
+    // by default, leave at least one-pixel padding at either end, and add
+    // lspace & rspace that may come from <mo> if we are an outermost
+    // embellished container (we fetch values from the core since they may use
+    // units that depend on style data, and style changes could have occurred
+    // in the core since our last visit there)
+    nscoord leftSpace = onePixel;
+    nscoord rightSpace = onePixel;
+    if (outermostEmbellished) {
+      nsEmbellishData coreData;
+      GetEmbellishDataFrom(mEmbellishData.coreFrame, coreData);
+      leftSpace += StyleVisibility()->mDirection ?
+                     coreData.trailingSpace : coreData.leadingSpace;
+      rightSpace += StyleVisibility()->mDirection ?
+                      coreData.leadingSpace : coreData.trailingSpace;
+    }
 
     //////////////////
     // Get shifts
@@ -393,8 +403,14 @@ nsMathMLmfracFrame::PlaceInternal(nsRenderingContext& aRenderingContext,
     nscoord slashMinHeight = slashRatio *
       std::min(2 * mLineThickness, slashMaxWidthConstant);
 
-    nscoord leadingSpace = std::max(padding, coreData.leadingSpace);
-    nscoord trailingSpace = std::max(padding, coreData.trailingSpace);
+    nscoord leadingSpace = padding;
+    nscoord trailingSpace = padding;
+    if (outermostEmbellished) {
+      nsEmbellishData coreData;
+      GetEmbellishDataFrom(mEmbellishData.coreFrame, coreData);
+      leadingSpace += coreData.leadingSpace;
+      trailingSpace += coreData.trailingSpace;
+    }
     nscoord delta;
     
     //           ___________

layout/mathml/nsMathMLmrowFrame.cpp

@@ -53,3 +53,17 @@ nsMathMLmrowFrame::AttributeChanged(int32_t  aNameSpaceID,
 
   return nsMathMLContainerFrame::AttributeChanged(aNameSpaceID, aAttribute, aModType);
 }
+
+/* virtual */ eMathMLFrameType
+nsMathMLmrowFrame::GetMathMLFrameType()
+{
+  if (!IsMrowLike()) {
+    nsIMathMLFrame* child = do_QueryFrame(mFrames.FirstChild());
+    if (child) {
+      // We only have one child, so we return the frame type of that child as if
+      // we didn't exist.
+      return child->GetMathMLFrameType();
+    }
+  }
+  return nsMathMLFrame::GetMathMLFrameType();
+}

layout/mathml/nsMathMLmrowFrame.h

@@ -32,6 +32,9 @@ public:
     return TransmitAutomaticDataForMrowLikeElement();
   }
 
+  virtual eMathMLFrameType
+  GetMathMLFrameType() MOZ_OVERRIDE; 
+
   bool
   IsMrowLike() MOZ_OVERRIDE {
     // <mrow> elements with a single child are treated identically to the case

layout/reftests/mathml/mo-lspace-rspace-4-ref.html

@@ -0,0 +1,31 @@
+<!doctype html>
+<html>
+  <body>
+    <p>
+      <math>
+        <mtext>_</mtext>
+        <mrow>
+          <mfrac>
+            <mo lspace="1em" rspace="2em">_</mo>
+            <mtext>_</mtext>
+          </mfrac>
+        </mrow>
+        <mtext>_</mtext>
+      </math>
+    </p>
+
+    <p>
+      <math>
+        <mtext>_</mtext>
+        <mrow>
+          <mfrac bevelled="true">
+            <mo lspace="1em" rspace="2em">_</mo>
+            <mtext>_</mtext>
+          </mfrac>
+        </mrow>
+        <mtext>_</mtext>
+      </math>
+    </p>
+
+  </body>
+</html>

layout/reftests/mathml/mo-lspace-rspace-4.html

@@ -0,0 +1,27 @@
+<!doctype html>
+<html>
+  <body>
+    <p>
+      <math>
+        <mtext>_</mtext>
+        <mfrac>
+          <mo lspace="1em" rspace="2em">_</mo>
+          <mtext>_</mtext>
+        </mfrac>
+        <mtext>_</mtext>
+      </math>
+    </p>
+
+    <p>
+      <math>
+        <mtext>_</mtext>
+        <mfrac bevelled="true">
+          <mo lspace="1em" rspace="2em">_</mo>
+          <mtext>_</mtext>
+        </mfrac>
+        <mtext>_</mtext>
+      </math>
+    </p>
+
+  </body>
+</html>

layout/reftests/mathml/reftest.list

@@ -143,6 +143,7 @@ skip-if(B2G) == maction-dynamic-1.html maction-dynamic-1-ref.html # bug 773482
 == mo-lspace-rspace.html mo-lspace-rspace-ref.html
 == mo-lspace-rspace-2.html mo-lspace-rspace-2-ref.html
 == mo-lspace-rspace-3.html mo-lspace-rspace-3-ref.html
+== mo-lspace-rspace-4.html mo-lspace-rspace-4-ref.html
 == mo-invisibleoperators.html mo-invisibleoperators-ref.html
 == mo-invisibleoperators-2.html mo-invisibleoperators-2-ref.html
 skip-if(B2G) == maction-dynamic-3.html maction-dynamic-3-ref.html # bug 773482