Bug 1305253 - Part 1. Use nsCSSClipPathInstance::ApplyBasicShapeClip when clip-path type is basic-shape or geometry-box. r=mstange

Before this patch, shouldApplyBasicShape will be set as true when the url of a
clip-path is not resolvable, for example:
  clip-path: url("#non-exist-id");

So we call nsCSSClipPathInstance::ApplyBasicShapeClip and early return even if
the clip-path's type is StyleShapeSourceType::URL. This patch aims to correct
this wrong behavior: nsCSSClipPathInstance::ApplyBasicShapeClip shoud be used
only when the type of clip-path is StyleShapeSourceType::Shape or
StyleShapeSourceType::Box.

MozReview-Commit-ID: 1ON4dEY9pva

--HG--
extra : rebase_source : 88e89526f4b57bcbb0a1db585884d578682d118c

layout/svg/nsCSSClipPathInstance.cpp

@@ -23,13 +23,13 @@ nsCSSClipPathInstance::ApplyBasicShapeClip(gfxContext& aContext,
                                            nsIFrame* aFrame)
 {
   auto& clipPathStyle = aFrame->StyleSVGReset()->mClipPath;
+
+#ifdef DEBUG
   StyleShapeSourceType type = clipPathStyle.GetType();
-  MOZ_ASSERT(type != StyleShapeSourceType::None, "unexpected none value");
-  // In the future nsCSSClipPathInstance may handle <clipPath> references as
-  // well. For the time being return early.
-  if (type == StyleShapeSourceType::URL) {
-    return;
-  }
+  MOZ_ASSERT(type == StyleShapeSourceType::Shape ||
+             type == StyleShapeSourceType::Box,
+             "This function is used with basic-shape and geometry-box only.");
+#endif
 
   nsCSSClipPathInstance instance(aFrame, clipPathStyle);
 

layout/svg/nsSVGIntegrationUtils.cpp

@@ -705,11 +705,6 @@ nsSVGIntegrationUtils::PaintMaskAndClipPath(const PaintFramesParams& aParams)
   nsSVGEffects::EffectProperties effectProperties =
     nsSVGEffects::GetEffectProperties(firstFrame);
 
-  bool isOK = effectProperties.HasNoFilterOrHasValidFilter();
-  nsSVGClipPathFrame *clipPathFrame = effectProperties.GetClipPathFrame(&isOK);
-
-  bool isTrivialClip = clipPathFrame ? clipPathFrame->IsTrivial() : true;
-
   gfxMatrix cssPxToDevPxMatrix = GetCSSPxToDevPxMatrix(frame);
   const nsStyleSVGReset *svgReset = firstFrame->StyleSVGReset();
   nsTArray<nsSVGMaskFrame *> maskFrames = effectProperties.GetMaskFrames();
@@ -734,11 +729,34 @@ nsSVGIntegrationUtils::PaintMaskAndClipPath(const PaintFramesParams& aParams)
   bool shouldGenerateMaskLayer = maskFrames.Length() == 1 && maskFrames[0];
 #endif
 
-  bool shouldGenerateClipMaskLayer = clipPathFrame && !isTrivialClip;
-  bool shouldApplyClipPath = clipPathFrame && isTrivialClip;
-  bool shouldApplyBasicShape = !clipPathFrame && svgReset->HasClipPath();
-  MOZ_ASSERT_IF(shouldGenerateClipMaskLayer,
-                !shouldApplyClipPath && !shouldApplyBasicShape);
+  bool isOK = effectProperties.HasNoFilterOrHasValidFilter();
+  nsSVGClipPathFrame *clipPathFrame = effectProperties.GetClipPathFrame(&isOK);
+  MOZ_ASSERT_IF(clipPathFrame,
+                svgReset->mClipPath.GetType() == StyleShapeSourceType::URL);
+
+  bool shouldGenerateClipMaskLayer = false;
+  bool shouldApplyClipPath = false;
+  bool shouldApplyBasicShape = false;
+  switch (svgReset->mClipPath.GetType()) {
+    case StyleShapeSourceType::URL:
+      if (clipPathFrame) {
+        if (clipPathFrame->IsTrivial()) {
+          shouldApplyClipPath = true;
+        } else {
+          shouldGenerateClipMaskLayer = true;
+        }
+      }
+      break;
+    case StyleShapeSourceType::Shape:
+    case StyleShapeSourceType::Box:
+      shouldApplyBasicShape = true;
+      break;
+    case StyleShapeSourceType::None:
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unsupported clip-path type.");
+      break;
+  }
 
   nsPoint offsetToBoundingBox;
   nsPoint offsetToUserSpace;