From 84cb2c35293caa4a1ece3b0f6c5cdab489f9a41e Mon Sep 17 00:00:00 2001
From: Matt Woodrow <mwoodrow@mozilla.com>
Date: Wed, 26 Sep 2012 10:47:41 +1200
Subject: [PATCH] Bug 793132 - Make sure that only display lists get the
 reference frame adjusted transform. r=roc

---
 layout/base/nsDisplayList.cpp          | 36 ++++++++++++++------------
 layout/base/nsDisplayList.h            |  3 +--
 layout/reftests/bugs/586683-1-ref.html |  6 +++--
 layout/reftests/bugs/586683-1.html     | 16 +++++-------
 4 files changed, 30 insertions(+), 31 deletions(-)

diff --git a/layout/base/nsDisplayList.cpp b/layout/base/nsDisplayList.cpp
index 02e2bdf6756c..5df3cf10dc00 100644
--- a/layout/base/nsDisplayList.cpp
+++ b/layout/base/nsDisplayList.cpp
@@ -3341,7 +3341,7 @@ nsDisplayTransform::GetResultingTransformMatrix(const nsIFrame* aFrame,
   return GetResultingTransformMatrixInternal(aFrame, aOrigin, aAppUnitsPerPixel,
                                              aBoundsOverride, aTransformOverride,
                                              aToMozOrigin, aToPerspectiveOrigin,
-                                             aChildPerspective, aOutAncestor, false);
+                                             aChildPerspective, aOutAncestor);
 }
 
 gfx3DMatrix
@@ -3353,8 +3353,7 @@ nsDisplayTransform::GetResultingTransformMatrixInternal(const nsIFrame* aFrame,
                                                         gfxPoint3D* aToMozOrigin,
                                                         gfxPoint3D* aToPerspectiveOrigin,
                                                         nscoord* aChildPerspective,
-                                                        nsIFrame** aOutAncestor,
-                                                        bool aRecursing)
+                                                        nsIFrame** aOutAncestor)
 {
   NS_PRECONDITION(aFrame || (aToMozOrigin && aBoundsOverride && aToPerspectiveOrigin &&
                              aTransformOverride && aChildPerspective),
@@ -3448,15 +3447,7 @@ nsDisplayTransform::GetResultingTransformMatrixInternal(const nsIFrame* aFrame,
   gfxPoint3D rounded(hasSVGTransforms ? newOrigin.x : NS_round(newOrigin.x), 
                      hasSVGTransforms ? newOrigin.y : NS_round(newOrigin.y), 
                      0);
-
-  /**
-   * Shift the coorindates to be relative to our reference frame instead of relative to this frame.
-   * When we have preserve-3d, our reference frame is already guaranteed to be an ancestor of the
-   * preserve-3d chain, so we only need to do this once.
-   */
-  if (!aRecursing) {
-    result.Translate(rounded);
-  }
+  
   if (aFrame && aFrame->Preserves3D() && nsLayoutUtils::Are3DTransformsEnabled()) {
       // Include the transform set on our parent
       NS_ASSERTION(aFrame->GetParent() &&
@@ -3467,7 +3458,7 @@ nsDisplayTransform::GetResultingTransformMatrixInternal(const nsIFrame* aFrame,
         GetResultingTransformMatrixInternal(aFrame->GetParent(),
                                             aOrigin - aFrame->GetPosition(),
                                             aAppUnitsPerPixel, nullptr, nullptr, nullptr,
-                                            nullptr, nullptr, aOutAncestor, true);
+                                            nullptr, nullptr, aOutAncestor);
       return nsLayoutUtils::ChangeMatrixBasis(rounded + toMozOrigin, result) * parent;
   }
 
@@ -3563,17 +3554,28 @@ const gfx3DMatrix&
 nsDisplayTransform::GetTransform(float aAppUnitsPerPixel)
 {
   if (mTransform.IsIdentity() || mCachedAppUnitsPerPixel != aAppUnitsPerPixel) {
+    gfxPoint3D newOrigin =
+      gfxPoint3D(NSAppUnitsToFloatPixels(mToReferenceFrame.x, aAppUnitsPerPixel),
+                 NSAppUnitsToFloatPixels(mToReferenceFrame.y, aAppUnitsPerPixel),
+                  0.0f);
     if (mTransformGetter) {
-      gfxPoint3D newOrigin =
-        gfxPoint3D(NSAppUnitsToFloatPixels(mToReferenceFrame.x, aAppUnitsPerPixel),
-                   NSAppUnitsToFloatPixels(mToReferenceFrame.y, aAppUnitsPerPixel),
-                    0.0f);
       mTransform = mTransformGetter(mFrame, aAppUnitsPerPixel);
       mTransform = nsLayoutUtils::ChangeMatrixBasis(newOrigin, mTransform);
     } else {
       mTransform =
         GetResultingTransformMatrix(mFrame, ToReferenceFrame(),
                                     aAppUnitsPerPixel);
+
+      /**
+       * Shift the coorindates to be relative to our reference frame instead of relative to this frame.
+       *  When we have preserve-3d, our reference frame is already guaranteed to be an ancestor of the
+       * preserve-3d chain, so we only need to do this once.
+       */
+      bool hasSVGTransforms = mFrame->IsSVGTransformed();
+      gfxPoint3D rounded(hasSVGTransforms ? newOrigin.x : NS_round(newOrigin.x), 
+                         hasSVGTransforms ? newOrigin.y : NS_round(newOrigin.y), 
+                         0);
+      mTransform.Translate(rounded);
       mCachedAppUnitsPerPixel = aAppUnitsPerPixel;
     }
   }
diff --git a/layout/base/nsDisplayList.h b/layout/base/nsDisplayList.h
index 34045bdc0f77..6261ab91d7f7 100644
--- a/layout/base/nsDisplayList.h
+++ b/layout/base/nsDisplayList.h
@@ -2517,8 +2517,7 @@ private:
                                                          gfxPoint3D* aToMozOrigin,
                                                          gfxPoint3D* aToPerspectiveOrigin,
                                                          nscoord* aChildPerspective,
-                                                         nsIFrame** aOutAncestor,
-                                                         bool aRecursing);
+                                                         nsIFrame** aOutAncestor);
 
   nsDisplayWrapList mStoredList;
   gfx3DMatrix mTransform;
diff --git a/layout/reftests/bugs/586683-1-ref.html b/layout/reftests/bugs/586683-1-ref.html
index 84c180efcc3b..f194e07351b7 100644
--- a/layout/reftests/bugs/586683-1-ref.html
+++ b/layout/reftests/bugs/586683-1-ref.html
@@ -7,12 +7,14 @@ body,html { width: 100%; height: 100%; padding: 0; }
 	position: absolute;
 	left: 300px;
 	top: 300px;
+    width: 100px;
+    height: 100px;
 	-moz-transform: scale(4);
-	border: 1px solid #888;
+    border: 1px solid #888;
 }
 </style>
 </head>
 <body>
-<div id="scale">Hello<div style="width:1px; height:1px; background:white;"></div></div>
+<div id="scale"></div>
 </body>
 </html>
diff --git a/layout/reftests/bugs/586683-1.html b/layout/reftests/bugs/586683-1.html
index 66fd3055c392..03502fcfe67a 100644
--- a/layout/reftests/bugs/586683-1.html
+++ b/layout/reftests/bugs/586683-1.html
@@ -6,19 +6,15 @@ body,html { width: 100%; height: 100%; padding: 0; }
 div {
 	position: absolute;
 	left: 300px;
-	top: 300px;
-	-moz-transform: scale(4);
-	border: 1px solid #888;
+    top: 300px;
+    width: 100px;
+    height: 100px;
+    -moz-transform: scale(4) perspective(1px);
+    border: 1px solid #888;
 }
 </style>
 </head>
 <body>
-<div>Hello<canvas width="1" height="1" id="c" style="display:block"></canvas></div>
-<script>
-var c = document.getElementById("c");
-var ctx = c.getContext("2d");
-ctx.fillStyle = "white";
-ctx.fillRect(0, 0, 1, 1);
-</script>
+<div></div>
 
 </body></html>