Bug 666041 patch 6.5: Add flag to nsHTMLReflowState & ComputeSize for measuring auto height. r=dbaron

layout/generic/nsHTMLReflowState.cpp

@@ -174,6 +174,7 @@ nsHTMLReflowState::nsHTMLReflowState(nsPresContext*           aPresContext,
   mFlags.mAssumingHScrollbar = mFlags.mAssumingVScrollbar = false;
   mFlags.mHasClearance = false;
   mFlags.mIsColumnBalancing = false;
+  mFlags.mIsFlexContainerMeasuringHeight = false;
   mFlags.mDummyParentReflowState = false;
 
   mDiscoveredClearance = nullptr;
@@ -2009,6 +2010,12 @@ nsHTMLReflowState::InitConstraints(nsPresContext* aPresContext,
         computeSizeFlags |= nsIFrame::eShrinkWrap;
       }
 
+      // If we're inside of a flexbox that needs to measure our auto height,
+      // pass that information along to ComputeSize().
+      if (mFlags.mIsFlexContainerMeasuringHeight) {
+        computeSizeFlags |= nsIFrame::eUseAutoHeight;
+      }
+
       nsSize size =
         frame->ComputeSize(rendContext,
                            nsSize(aContainingBlockWidth,
@@ -2487,6 +2494,9 @@ nsHTMLReflowState::ComputeMinMaxValues(nscoord aContainingBlockWidth,
   // depends on the content height. Treat them like 'auto'
   // Likewise, check for calc() on internal table elements; calc() on
   // such elements is unsupported.
+  // Likewise, if we're a child of a flex container who's measuring our
+  // intrinsic height, then we want to disregard our min-height.
+
   // NOTE: We treat "min-height:auto" as "0" for the purpose of this code,
   // since that's what it means in all cases except for on flex items -- and
   // even there, we're supposed to ignore it (i.e. treat it as 0) until the
@@ -2496,7 +2506,8 @@ nsHTMLReflowState::ComputeMinMaxValues(nscoord aContainingBlockWidth,
       (NS_AUTOHEIGHT == aContainingBlockHeight &&
        minHeight.HasPercent()) ||
       (mFrameType == NS_CSS_FRAME_TYPE_INTERNAL_TABLE &&
-       minHeight.IsCalcUnit())) {
+       minHeight.IsCalcUnit()) ||
+      mFlags.mIsFlexContainerMeasuringHeight) {
     mComputedMinHeight = 0;
   } else {
     mComputedMinHeight = ComputeHeightValue(aContainingBlockHeight, 
@@ -2510,13 +2521,16 @@ nsHTMLReflowState::ComputeMinMaxValues(nscoord aContainingBlockWidth,
     mComputedMaxHeight = NS_UNCONSTRAINEDSIZE;  // no limit
   } else {
     // Check for percentage based values and a containing block height that
-    // depends on the content height. Treat them like 'auto'
+    // depends on the content height. Treat them like 'none'
     // Likewise, check for calc() on internal table elements; calc() on
     // such elements is unsupported.
+    // Likewise, if we're a child of a flex container who's measuring our
+    // intrinsic height, then we want to disregard our max-height.
     if ((NS_AUTOHEIGHT == aContainingBlockHeight && 
          maxHeight.HasPercent()) ||
         (mFrameType == NS_CSS_FRAME_TYPE_INTERNAL_TABLE &&
-         maxHeight.IsCalcUnit())) {
+         maxHeight.IsCalcUnit()) ||
+        mFlags.mIsFlexContainerMeasuringHeight) {
       mComputedMaxHeight = NS_UNCONSTRAINEDSIZE;
     } else {
       mComputedMaxHeight = ComputeHeightValue(aContainingBlockHeight,