Bug 1202703 - Part 1 - CreateRenderingContext can fail. r=mattwoodrow

gfx/src/nsDeviceContext.cpp

@@ -413,9 +413,11 @@ nsDeviceContext::CreateRenderingContext()
       gfxPlatform::GetPlatform()->CreateDrawTargetForSurface(printingSurface,
                                                              gfx::IntSize(mWidth, mHeight));
 
+    // This can legitimately happen - CreateDrawTargetForSurface will fail
+    // to create a draw target if the size is too large, for instance.
     if (!dt) {
-        gfxCriticalError() << "Failed to create draw target in device context sized " << mWidth << "x" << mHeight << " and pointers " << hexa(mPrintingSurface) << " and " << hexa(printingSurface);
+        gfxCriticalNote << "Failed to create draw target in device context sized " << mWidth << "x" << mHeight << " and pointers " << hexa(mPrintingSurface) << " and " << hexa(printingSurface);
-        MOZ_CRASH("Cannot CreateDrawTargetForSurface");
+        return nullptr;
     }
 
 #ifdef XP_MACOSX

layout/base/nsPresShell.cpp

@@ -2910,11 +2910,15 @@ PresShell::CreateReferenceRenderingContext()
   if (mPresContext->IsScreen()) {
     rc = new gfxContext(gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget());
   } else {
-    // We assume the devCtx has positive width and height for this call
+    // We assume the devCtx has positive width and height for this call.
+    // However, width and height, may be outside of the reasonable range
+    // so rc may still be null.
     rc = devCtx->CreateRenderingContext();
+    if (!rc) {
+      return nullptr;
+    }
   }
 
-  MOZ_ASSERT(rc, "shouldn't break promise to return non-null");
   return rc.forget();
 }
 
@@ -8969,6 +8973,7 @@ PresShell::DoReflow(nsIFrame* target, bool aInterruptible)
 
   nsIFrame* rootFrame = mFrameConstructor->GetRootFrame();
 
+  // CreateReferenceRenderingContext can return nullptr
   nsRenderingContext rcx(CreateReferenceRenderingContext());
 
 #ifdef DEBUG
@@ -10902,6 +10907,7 @@ nsIPresShell::SyncWindowProperties(nsView* aView)
 {
   nsIFrame* frame = aView->GetFrame();
   if (frame && mPresContext) {
+    // CreateReferenceRenderingContext can return nullptr
     nsRenderingContext rcx(CreateReferenceRenderingContext());
     nsContainerFrame::SyncWindowProperties(mPresContext, frame, aView, &rcx, 0);
   }

layout/generic/nsSimplePageSequenceFrame.cpp

@@ -645,6 +645,7 @@ nsSimplePageSequenceFrame::PrePrintNextPage(nsITimerCallback* aCallback, bool* a
       mCalledBeginPage = true;
       
       nsRefPtr<gfxContext> renderingContext = dc->CreateRenderingContext();
+      NS_ENSURE_TRUE(renderingContext, NS_ERROR_OUT_OF_MEMORY);
 
       nsRefPtr<gfxASurface> renderingSurface =
           renderingContext->CurrentSurface();
@@ -773,7 +774,11 @@ nsSimplePageSequenceFrame::PrintNextPage()
 
       PR_PL(("SeqFr::PrintNextPage -> %p PageNo: %d", pf, mPageNum));
 
-      nsRenderingContext renderingContext(dc->CreateRenderingContext());
+      // CreateRenderingContext can fail
+      nsRefPtr<gfxContext> gCtx = dc->CreateRenderingContext();
+      NS_ENSURE_TRUE(gCtx, NS_ERROR_OUT_OF_MEMORY);
+
+      nsRenderingContext renderingContext(gCtx);
 
       nsRect drawingRect(nsPoint(0, 0), currentPage->GetSize());
       nsRegion drawingRegion(drawingRect);

layout/printing/nsPrintEngine.cpp

@@ -2484,7 +2484,12 @@ nsPrintEngine::DoPrint(nsPrintObject * aPO)
         // temporarily creating rendering context
         // which is needed to find the selection frames
         // mPrintDC must have positive width and height for this call
-        nsRenderingContext rc(mPrt->mPrintDC->CreateRenderingContext());
+
+        // CreateRenderingContext can fail for large dimensions
+        nsRefPtr<gfxContext> gCtx = mPrt->mPrintDC->CreateRenderingContext();
+        NS_ENSURE_TRUE(gCtx, NS_ERROR_OUT_OF_MEMORY);
+
+        nsRenderingContext rc(gCtx);
 
         // find the starting and ending page numbers
         // via the selection