Create a rendering context before calling GetPrefSize and friends and assert in those methods that we have one. b=379090 r+sr=dbaron

layout/xul/base/src/nsBox.cpp

@@ -456,6 +456,8 @@ nsBox::GetLayoutManager(nsIBoxLayout** aLayout)
 nsSize
 nsBox::GetPrefSize(nsBoxLayoutState& aState)
 {
+  NS_ASSERTION(aState.GetRenderingContext(), "must have rendering context");
+
   nsSize pref(0,0);
   DISPLAY_PREF_SIZE(this, pref);
 
@@ -475,6 +477,8 @@ nsBox::GetPrefSize(nsBoxLayoutState& aState)
 nsSize
 nsBox::GetMinSize(nsBoxLayoutState& aState)
 {
+  NS_ASSERTION(aState.GetRenderingContext(), "must have rendering context");
+
   nsSize min(0,0);
   DISPLAY_MIN_SIZE(this, min);
 
@@ -495,6 +499,8 @@ nsBox::GetMinSizeForScrollArea(nsBoxLayoutState& aBoxLayoutState)
 nsSize
 nsBox::GetMaxSize(nsBoxLayoutState& aState)
 {
+  NS_ASSERTION(aState.GetRenderingContext(), "must have rendering context");
+
   nsSize max(NS_INTRINSICSIZE, NS_INTRINSICSIZE);
   DISPLAY_MAX_SIZE(this, max);
 
@@ -547,6 +553,8 @@ nsBox::IsCollapsed(nsBoxLayoutState& aState)
 nsresult
 nsIFrame::Layout(nsBoxLayoutState& aState)
 {
+  NS_ASSERTION(aState.GetRenderingContext(), "must have rendering context");
+
   nsBox *box = NS_STATIC_CAST(nsBox*, this);
   DISPLAY_LAYOUT(box);
 

layout/xul/base/src/nsBoxFrame.cpp

@@ -804,6 +804,9 @@ nsBoxFrame::Reflow(nsPresContext*          aPresContext,
 nsSize
 nsBoxFrame::GetPrefSize(nsBoxLayoutState& aBoxLayoutState)
 {
+  NS_ASSERTION(aBoxLayoutState.GetRenderingContext(),
+               "must have rendering context");
+
   nsSize size(0,0);
   DISPLAY_PREF_SIZE(this, size);
   if (!DoesNeedRecalc(mPrefSize)) {
@@ -860,6 +863,9 @@ nsBoxFrame::GetBoxAscent(nsBoxLayoutState& aBoxLayoutState)
 nsSize
 nsBoxFrame::GetMinSize(nsBoxLayoutState& aBoxLayoutState)
 {
+  NS_ASSERTION(aBoxLayoutState.GetRenderingContext(),
+               "must have rendering context");
+
   nsSize size(0,0);
   DISPLAY_MIN_SIZE(this, size);
   if (!DoesNeedRecalc(mMinSize)) {
@@ -893,6 +899,9 @@ nsBoxFrame::GetMinSize(nsBoxLayoutState& aBoxLayoutState)
 nsSize
 nsBoxFrame::GetMaxSize(nsBoxLayoutState& aBoxLayoutState)
 {
+  NS_ASSERTION(aBoxLayoutState.GetRenderingContext(),
+               "must have rendering context");
+
   nsSize size(NS_INTRINSICSIZE, NS_INTRINSICSIZE);
   DISPLAY_MAX_SIZE(this, size);
   if (!DoesNeedRecalc(mMaxSize)) {

layout/xul/base/src/nsSplitterFrame.cpp

@@ -724,9 +724,11 @@ nsSplitterFrameInner::MouseDown(nsIDOMEvent* aMouseEvent)
   if (childIndex == 0 || childIndex == childCount - 1)
     return NS_OK;
 
-  // XXXbz using this state for GetPrefSize/GetMinSize is wrong.  It
-  // needs a rendering context!
-  nsBoxLayoutState state(outerPresContext);
+  nsCOMPtr<nsIRenderingContext> rc;
+  nsresult rv = outerPresContext->PresShell()->
+                  CreateRenderingContext(mOuter, getter_AddRefs(rc));
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsBoxLayoutState state(outerPresContext, rc);
   mCurrentPos = 0;
   mPressed = PR_TRUE;
 
@@ -753,7 +755,6 @@ nsSplitterFrameInner::MouseDown(nsIDOMEvent* aMouseEvent)
   while (nsnull != childBox) 
   { 
     nsIContent* content = childBox->GetContent();
-    nsresult rv;
     nsIDocument* doc = content->GetOwnerDoc();
     nsIAtom* atom;
     if (doc) {