Bug 1342800 - ComputeSize should not treat iframe as object r=firefox-svg-reviewers,longsonr

We should not treat <iframe> as <object> for SVG, otherwise there will
be unexpected sizing and other webcompat problem (e.g. getScreenCTM).

It behaved correctly before, the change was introduced to solve a double
zooming problem (bug 843480) for <iframe>. Actually the zooming problem
can be solved by avoiding zooming when the window frame is an <iframe>.

Differential Revision: https://phabricator.services.mozilla.com/D28313

--HG--
extra : moz-landing-system : lando

dom/svg/test/test_getCTM.html

@@ -70,31 +70,31 @@ function runTest() {
   /* Tests the consistency with farthestViewportElement
      (code is from test_viewport.html) */
   // root.farthestViewportElement == null (but actually == root)
-  is((function() { try { return root.getScreenCTM().e; } catch (e) { return e; } })(), 91.5, "root.getScreenCTM().e");
+  is((function() { try { return root.getScreenCTM().e; } catch (e) { return e; } })(), 11, "root.getScreenCTM().e");
-  is((function() { try { return root.getScreenCTM().f; } catch (e) { return e; } })(), 33, "root.getScreenCTM().f");
+  is((function() { try { return root.getScreenCTM().f; } catch (e) { return e; } })(), 22, "root.getScreenCTM().f");
   // inner.farthestViewportElement == root
-  is((function() { try { return inner.getScreenCTM().e; } catch (e) { return e; } })(), 97.5, "inner.getScreenCTM().e");
+  is((function() { try { return inner.getScreenCTM().e; } catch (e) { return e; } })(), 15, "inner.getScreenCTM().e");
-  is((function() { try { return inner.getScreenCTM().f; } catch (e) { return e; } })(), 42, "inner.getScreenCTM().f");
+  is((function() { try { return inner.getScreenCTM().f; } catch (e) { return e; } })(), 28, "inner.getScreenCTM().f");
   // g1.farthestViewportElement == root
-  is((function() { try { return g1.getScreenCTM().e; } catch (e) { return e; } })(), 142.5, "g1.getScreenCTM().e");
+  is((function() { try { return g1.getScreenCTM().e; } catch (e) { return e; } })(), 45, "g1.getScreenCTM().e");
-  is((function() { try { return g1.getScreenCTM().f; } catch (e) { return e; } })(), 102, "g1.getScreenCTM().f");
+  is((function() { try { return g1.getScreenCTM().f; } catch (e) { return e; } })(), 68, "g1.getScreenCTM().f");
   // outer.farthestViewportElement == null (but actually == root)
-  is((function() { try { return outer.getScreenCTM().e; } catch (e) { return e; } })(), 144, "outer.getScreenCTM().e");
+  is((function() { try { return outer.getScreenCTM().e; } catch (e) { return e; } })(), 46, "outer.getScreenCTM().e");
-  is((function() { try { return outer.getScreenCTM().f; } catch (e) { return e; } })(), 103.5, "outer.getScreenCTM().f");
+  is((function() { try { return outer.getScreenCTM().f; } catch (e) { return e; } })(), 69, "outer.getScreenCTM().f");
   // outer.farthestViewportElement == null (but actually == root)
   is((function() { try { return outer2.getScreenCTM().e; } catch (e) { return e; } })(), -19, "outer2.getScreenCTM().e");
   is((function() { try { return outer2.getScreenCTM().f; } catch (e) { return e; } })(), -8, "outer2.getScreenCTM().f");
   // g2.farthestViewportElement == outer (but actually == root)
-  is((function() { try { return g2.getScreenCTM().e; } catch (e) { return e; } })(), 1044, "g2.getScreenCTM().e");
+  is((function() { try { return g2.getScreenCTM().e; } catch (e) { return e; } })(), 646, "g2.getScreenCTM().e");
-  is((function() { try { return g2.getScreenCTM().f; } catch (e) { return e; } })(), 1153.5, "g2.getScreenCTM().f");
+  is((function() { try { return g2.getScreenCTM().f; } catch (e) { return e; } })(), 769, "g2.getScreenCTM().f");
   // g3.farthestViewportElement == null (but actually == null)
   is((function() { try { return g3.getScreenCTM(); } catch (e) { return e; } })(), null, "g3.getScreenCTM()");
   // symbolRect.farthestViewportElement == root
-  is((function() { try { return symbolRect.getScreenCTM().e; } catch (e) { return e; } })(), 202.5, "symbolRect.getScreenCTM().e");
+  is((function() { try { return symbolRect.getScreenCTM().e; } catch (e) { return e; } })(), 85, "symbolRect.getScreenCTM().e");
-  is((function() { try { return symbolRect.getScreenCTM().f; } catch (e) { return e; } })(), 162, "symbolRect.getScreenCTM().f");
+  is((function() { try { return symbolRect.getScreenCTM().f; } catch (e) { return e; } })(), 108, "symbolRect.getScreenCTM().f");
   // fO.farthestViewportElement == root
-  is((function() { try { return fO.getScreenCTM().e; } catch (e) { return e; } })(), 99, "symbolRect.getScreenCTM().e");
+  is((function() { try { return fO.getScreenCTM().e; } catch (e) { return e; } })(), 16, "symbolRect.getScreenCTM().e");
-  is((function() { try { return fO.getScreenCTM().f; } catch (e) { return e; } })(), 43.5, "symbolRect.getScreenCTM().f");
+  is((function() { try { return fO.getScreenCTM().f; } catch (e) { return e; } })(), 29, "symbolRect.getScreenCTM().f");
   // g5.farthestViewportElement == root
   is((function() { try { return g5.getScreenCTM(); } catch (e) { return e; } })(), null, "g5.getScreenCTM()");
 

layout/svg/nsSVGOuterSVGFrame.cpp

@@ -308,8 +308,11 @@ LogicalSize nsSVGOuterSVGFrame::ComputeSize(
     NS_ASSERTION(aCBSize.ISize(aWM) != NS_AUTOHEIGHT &&
                      aCBSize.BSize(aWM) != NS_AUTOHEIGHT,
                  "root should not have auto-width/height containing block");
-    cbSize.ISize(aWM) *= PresContext()->GetFullZoom();
+
-    cbSize.BSize(aWM) *= PresContext()->GetFullZoom();
+    if (!IsContainingWindowElementOfType(nullptr, nsGkAtoms::iframe)) {
+      cbSize.ISize(aWM) *= PresContext()->GetFullZoom();
+      cbSize.BSize(aWM) *= PresContext()->GetFullZoom();
+    }
 
     // We also need to honour the width and height attributes' default values
     // of 100% when we're the root of a browsing context.  (GetIntrinsicSize()
@@ -427,7 +430,8 @@ void nsSVGOuterSVGFrame::Reflow(nsPresContext* aPresContext,
     changeBits |= COORD_CONTEXT_CHANGED;
     svgElem->SetViewportSize(newViewportSize);
   }
-  if (mFullZoom != PresContext()->GetFullZoom()) {
+  if (mFullZoom != PresContext()->GetFullZoom() &&
+      !IsContainingWindowElementOfType(nullptr, nsGkAtoms::iframe)) {
     changeBits |= FULL_ZOOM_CHANGED;
     mFullZoom = PresContext()->GetFullZoom();
   }
@@ -873,8 +877,9 @@ gfxMatrix nsSVGOuterSVGFrame::GetCanvasTM() {
 //----------------------------------------------------------------------
 // Implementation helpers
 
-bool nsSVGOuterSVGFrame::IsRootOfReplacedElementSubDoc(
+template <typename... Args>
-    nsIFrame** aEmbeddingFrame) {
+bool nsSVGOuterSVGFrame::IsContainingWindowElementOfType(
+    nsIFrame** aContainingWindowFrame, Args... aArgs) const {
   if (!mContent->GetParent()) {
     // Our content is the document element
     nsCOMPtr<nsIDocShell> docShell = PresContext()->GetDocShell();
@@ -885,24 +890,27 @@ bool nsSVGOuterSVGFrame::IsRootOfReplacedElementSubDoc(
 
     if (window) {
       RefPtr<Element> frameElement = window->GetFrameElement();
-      if (frameElement &&
+      if (frameElement && frameElement->IsAnyOfHTMLElements(aArgs...)) {
-          frameElement->IsAnyOfHTMLElements(nsGkAtoms::object, nsGkAtoms::embed,
+        if (aContainingWindowFrame) {
-                                            nsGkAtoms::iframe)) {
+          *aContainingWindowFrame = frameElement->GetPrimaryFrame();
-        // Our document is inside an HTML 'object', 'embed' or 'iframe' element
+          NS_ASSERTION(*aContainingWindowFrame, "Yikes, no frame!");
-        if (aEmbeddingFrame) {
-          *aEmbeddingFrame = frameElement->GetPrimaryFrame();
-          NS_ASSERTION(*aEmbeddingFrame, "Yikes, no embedding frame!");
         }
         return true;
       }
     }
   }
-  if (aEmbeddingFrame) {
+  if (aContainingWindowFrame) {
-    *aEmbeddingFrame = nullptr;
+    *aContainingWindowFrame = nullptr;
   }
   return false;
 }
 
+bool nsSVGOuterSVGFrame::IsRootOfReplacedElementSubDoc(
+    nsIFrame** aEmbeddingFrame) {
+  return IsContainingWindowElementOfType(aEmbeddingFrame, nsGkAtoms::object,
+                                         nsGkAtoms::embed);
+}
+
 bool nsSVGOuterSVGFrame::IsRootOfImage() {
   if (!mContent->GetParent()) {
     // Our content is the document element

layout/svg/nsSVGOuterSVGFrame.h

@@ -191,6 +191,11 @@ class nsSVGOuterSVGFrame final : public nsSVGDisplayContainerFrame,
 
   bool mViewportInitialized;
   bool mIsRootContent;
+
+ private:
+  template <typename... Args>
+  bool IsContainingWindowElementOfType(nsIFrame** aContainingWindowFrame,
+                                       Args... aArgs) const;
 };
 
 ////////////////////////////////////////////////////////////////////////