Bug 485149 - Using box-shadow on a <fieldset> with <legend> does not follow box shape. r=roc

layout/base/nsCSSRendering.cpp

@@ -1214,7 +1214,8 @@ nsCSSRendering::PaintBoxShadowOuter(nsPresContext* aPresContext,
   } else {
     nativeTheme = false;
     nscoord twipsRadii[8];
-    NS_ASSERTION(aFrameArea.Size() == aForFrame->GetSize(), "unexpected size");
+    NS_ASSERTION(aFrameArea.Size() == aForFrame->VisualBorderRectRelativeToSelf().Size(),
+                 "unexpected size");
     hasBorderRadius = aForFrame->GetBorderRadii(twipsRadii);
     if (hasBorderRadius) {
       ComputePixelRadii(twipsRadii, twipsPerPixel, &borderRadii);

layout/base/nsDisplayList.cpp

@@ -2385,7 +2385,7 @@ void
 nsDisplayBoxShadowOuter::Paint(nsDisplayListBuilder* aBuilder,
                                nsRenderingContext* aCtx) {
   nsPoint offset = ToReferenceFrame();
-  nsRect borderRect = nsRect(offset, mFrame->GetSize());
+  nsRect borderRect = mFrame->VisualBorderRectRelativeToSelf() + offset;
   nsPresContext* presContext = mFrame->PresContext();
   nsAutoTArray<nsRect,10> rects;
   ComputeDisjointRectangles(mVisibleRegion, &rects);

layout/forms/nsFieldSetFrame.cpp

@@ -3,9 +3,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-// YY need to pass isMultiple before create called
-
-//#include "nsFormControlFrame.h"
 #include "nsContainerFrame.h"
 #include "nsLegendFrame.h"
 #include "nsIDOMNode.h"
@@ -13,7 +10,6 @@
 #include "nsIDOMHTMLLegendElement.h"
 #include "nsCSSRendering.h"
 #include <algorithm>
-//#include "nsIDOMHTMLCollection.h"
 #include "nsIContent.h"
 #include "nsIFrame.h"
 #include "nsISupports.h"
@@ -35,7 +31,7 @@ using namespace mozilla::layout;
 
 class nsLegendFrame;
 
-class nsFieldSetFrame : public nsContainerFrame {
+class nsFieldSetFrame MOZ_FINAL : public nsContainerFrame {
 public:
   NS_DECL_FRAMEARENA_HELPERS
 
@@ -55,6 +51,21 @@ public:
                              uint32_t aFlags) MOZ_OVERRIDE;
   virtual nscoord GetBaseline() const;
 
+  /**
+   * The area to paint box-shadows around.  It's the border rect except
+   * when there's a <legend> we offset the y-position to the center of it.
+   */
+  virtual nsRect VisualBorderRectRelativeToSelf() const MOZ_OVERRIDE {
+    nscoord topBorder = StyleBorder()->GetComputedBorderWidth(NS_SIDE_TOP);
+    nsRect r(nsPoint(0,0), GetSize());
+    if (topBorder < mLegendRect.height) {
+      nscoord yoff = (mLegendRect.height - topBorder) / 2;
+      r.y += yoff;
+      r.height -= yoff;
+    }
+    return r;
+  }
+
   NS_IMETHOD Reflow(nsPresContext*           aPresContext,
                     nsHTMLReflowMetrics&     aDesiredSize,
                     const nsHTMLReflowState& aReflowState,
@@ -229,20 +240,14 @@ void
 nsFieldSetFrame::PaintBorderBackground(nsRenderingContext& aRenderingContext,
     nsPoint aPt, const nsRect& aDirtyRect, uint32_t aBGFlags)
 {
-  const nsStyleBorder* borderStyle = StyleBorder();
-       
-  nscoord topBorder = borderStyle->GetComputedBorderWidth(NS_SIDE_TOP);
-  nscoord yoff = 0;
-  nsPresContext* presContext = PresContext();
-     
   // if the border is smaller than the legend. Move the border down
   // to be centered on the legend. 
   // FIXME: This means border-radius clamping is incorrect; we should
   // override nsIFrame::GetBorderRadii.
-  if (topBorder < mLegendRect.height)
-    yoff = (mLegendRect.height - topBorder)/2;
-      
-  nsRect rect(aPt.x, aPt.y + yoff, mRect.width, mRect.height - yoff);
+  nsRect rect = VisualBorderRectRelativeToSelf();
+  nscoord yoff = rect.y;
+  rect += aPt;
+  nsPresContext* presContext = PresContext();
 
   nsCSSRendering::PaintBackground(presContext, aRenderingContext, this,
                                   aDirtyRect, rect, aBGFlags);
@@ -251,6 +256,7 @@ nsFieldSetFrame::PaintBorderBackground(nsRenderingContext& aRenderingContext,
                                       this, rect, aDirtyRect);
 
    if (mLegendFrame) {
+     nscoord topBorder = StyleBorder()->GetComputedBorderWidth(NS_SIDE_TOP);
 
     // Use the rect of the legend frame, not mLegendRect, so we draw our
     // border under the legend's left and right margins.

layout/generic/nsIFrame.h

@@ -1008,6 +1008,14 @@ public:
   nsRect GetContentRect() const;
   nsRect GetContentRectRelativeToSelf() const;
 
+  /**
+   * The area to paint box-shadows around.  The default is the border rect.
+   * (nsFieldSetFrame overrides this).
+   */
+  virtual nsRect VisualBorderRectRelativeToSelf() const {
+    return nsRect(0, 0, mRect.width, mRect.height);
+  }
+
   /**
    * Get the size, in app units, of the border radii. It returns FALSE iff all
    * returned radii == 0 (so no border radii), TRUE otherwise.

layout/reftests/box-shadow/fieldset-ref.html

@@ -0,0 +1,95 @@
+<!DOCTYPE HTML>
+<html><head>
+    <meta charset="utf-8">
+    <title>Testcase for bug 485149</title>
+    <style type="text/css">
+
+        html,body {
+            color:black; background-color:white; font-size:16px; padding:0; margin:0;
+        }
+	
+
+body {padding:20px;}
+
+field {
+  display:block;
+  overflow:hidden;
+  background:yellow;
+
+  box-shadow:0 0 5px 5px #cccccc; 
+  border:1px solid #000000;
+  border-radius:7px;
+  width:200px;
+  height:50px;
+  margin-left:5px;
+  margin-right:2px;
+  padding:10px;
+  border-box;
+}
+
+.with-legend {
+  margin-top:8px;
+  height:42px;
+}
+
+p { height:40px; margin:0; }
+
+#mask1 {
+ position:absolute;
+ left:0;
+ top:0;
+ background:black;
+ z-index:1;
+ width:150px;
+ height:700px;
+}
+
+#mask2 {
+ position:absolute;
+ left:170px;
+ top:330px;
+ background:black;
+ z-index:1;
+ width:150px;
+ height:300px;
+}
+
+#mask3 {
+ position:absolute;
+ left:0;
+ top:380px;
+ background:black;
+ z-index:1;
+ width:300px;
+ height:300px;
+}
+
+</style>
+</head>
+<body>
+
+<field class="with-legend">
+1
+</field>
+
+<p></p>
+<field class="with-legend" style="position:relative">
+2
+</field>
+
+<p></p>
+<field>
+3
+</field>
+
+<p></p>
+<field class="with-legend" style="border-color:transparent">
+4
+</field>
+
+<div id="mask1"></div>
+<div id="mask2"></div>
+<div id="mask3"></div>
+
+</body>
+</html>

layout/reftests/box-shadow/fieldset.html

@@ -0,0 +1,90 @@
+<!DOCTYPE HTML>
+<html><head>
+    <meta charset="utf-8">
+    <title>Testcase for bug 485149</title>
+    <style type="text/css">
+
+        html,body {
+            color:black; background-color:white; font-size:16px; padding:0; margin:0;
+        }
+	
+
+body {padding:20px;}
+
+fieldset {
+  overflow:hidden;
+  background:yellow;
+
+  box-shadow:0 0 5px 5px #cccccc; 
+  border:1px solid #000000;
+  border-radius:7px;
+  width:200px;
+  height:50px;
+  margin-left:5px;
+  margin-right:2px;
+  padding:10px;
+}
+
+legend { height:16px; }
+
+p { height:40px; margin:0; }
+
+#mask1 {
+ position:absolute;
+ left:0;
+ top:0;
+ background:black;
+ z-index:1;
+ width:150px;
+ height:700px;
+}
+
+#mask2 {
+ position:absolute;
+ left:170px;
+ top:330px;
+ background:black;
+ z-index:1;
+ width:150px;
+ height:300px;
+}
+
+#mask3 {
+ position:absolute;
+ left:0;
+ top:380px;
+ background:black;
+ z-index:1;
+ width:300px;
+ height:300px;
+}
+
+</style>
+</head>
+<body>
+
+<fieldset><legend>Legend</legend>
+1
+</fieldset>
+
+<p></p>
+<fieldset style="position:relative;"><legend>Legend</legend>
+2
+</fieldset>
+
+<p></p>
+<fieldset>
+3
+</fieldset>
+
+<p></p>
+<fieldset><legend style="width:150px;"></legend>
+4
+</fieldset>
+
+<div id="mask1"></div>
+<div id="mask2"></div>
+<div id="mask3"></div>
+
+</body>
+</html>

layout/reftests/box-shadow/reftest.list

@@ -25,3 +25,4 @@ random-if(d2d) == boxshadow-threecorners.html boxshadow-threecorners-ref.html
 == overflow-not-scrollable-2.html overflow-not-scrollable-2-ref.html
 fails-if(Android) == 611574-1.html 611574-1-ref.html
 fails-if(Android) == 611574-2.html 611574-2-ref.html
+fuzzy-if(winWidget,5,30) == fieldset.html fieldset-ref.html # minor anti-aliasing problem on Windows