Bug 763689 patch 3: Support min-height:auto in computed style, and add special cases as necessary wherever it's read. r=dbaron

layout/base/crashtests/crashtests.list

@@ -45,7 +45,7 @@ asserts(6-12) load 265986-1.html # Bug 512405
 load 265999-1.html
 load 266222-1.html
 asserts(3-7) load 266360-1.html # bug 575011 / bug 576358
-asserts(3) load 266445-1.html # Bug 575011
+asserts(4) load 266445-1.html # Bug 575011
 load 268157-1.html
 load 269566-1.html
 load 272647-1.html

layout/base/nsLayoutUtils.cpp

@@ -2389,7 +2389,8 @@ GetPercentHeight(const nsStyleCoord& aStyle,
     if (minh > h)
       h = minh;
   } else {
-    NS_ASSERTION(pos->mMinHeight.HasPercent(),
+    NS_ASSERTION(pos->mMinHeight.HasPercent() ||
+                 pos->mMinHeight.GetUnit() == eStyleUnit_Auto,
                  "unknown min-height unit");
   }
 
@@ -2540,12 +2541,18 @@ nsLayoutUtils::IntrinsicForContainer(nsRenderingContext *aRenderingContext,
 
     // Handle elements with an intrinsic ratio (or size) and a specified
     // height, min-height, or max-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
+    // flex container explicitly considers it.
     const nsStyleCoord &styleHeight = stylePos->mHeight;
     const nsStyleCoord &styleMinHeight = stylePos->mMinHeight;
     const nsStyleCoord &styleMaxHeight = stylePos->mMaxHeight;
+
     if (styleHeight.GetUnit() != eStyleUnit_Auto ||
-        !(styleMinHeight.GetUnit() == eStyleUnit_Coord &&
-          styleMinHeight.GetCoordValue() == 0) ||
+        !(styleMinHeight.GetUnit() == eStyleUnit_Auto || 
+          (styleMinHeight.GetUnit() == eStyleUnit_Coord &&
+           styleMinHeight.GetCoordValue() == 0)) ||
         styleMaxHeight.GetUnit() != eStyleUnit_None) {
 
       nsSize ratio = aFrame->GetIntrinsicRatio();

layout/generic/crashtests/crashtests.list

@@ -14,7 +14,7 @@ load 310556-1.xhtml
 load 322780-1.xul
 load 323381-1.html
 load 323381-2.html
-asserts-if(gtk2Widget,13) load 323386-1.html # Bug 575011
+asserts-if(gtk2Widget,12-13) load 323386-1.html # Bug 575011
 load 323389-1.html
 load 323389-2.html
 load 323493-1.html
@@ -293,7 +293,7 @@ load 495875-1.html
 load 495875-2.html
 load 499862-1.html
 load 499857-1.html
-asserts(10-90) asserts-if(winWidget,3-108) load 499885-1.xhtml # nscoord_MAX assertions (bug 575011), plus bug 570436 on some versions of windows
+asserts(4-90) asserts-if(winWidget,3-108) load 499885-1.xhtml # nscoord_MAX assertions (bug 575011), plus bug 570436 on some versions of windows
 load 501535-1.html
 load 503961-1.xhtml
 load 503961-2.html

layout/generic/nsHTMLReflowState.cpp

@@ -2487,8 +2487,13 @@ 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.
+  // 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
+  // flex container explicitly considers it.
   const nsStyleCoord &minHeight = mStylePosition->mMinHeight;
-  if ((NS_AUTOHEIGHT == aContainingBlockHeight &&
+  if (eStyleUnit_Auto == minHeight.GetUnit() ||
+      (NS_AUTOHEIGHT == aContainingBlockHeight &&
        minHeight.HasPercent()) ||
       (mFrameType == NS_CSS_FRAME_TYPE_INTERNAL_TABLE &&
        minHeight.IsCalcUnit())) {

layout/style/nsComputedDOMStyle.cpp

@@ -3352,7 +3352,17 @@ nsIDOMCSSValue*
 nsComputedDOMStyle::DoGetMinHeight()
 {
   nsROCSSPrimitiveValue *val = GetROCSSPrimitiveValue();
-  SetValueToCoord(val, GetStylePosition()->mMinHeight, true,
+  nsStyleCoord minHeight = GetStylePosition()->mMinHeight;
+
+  if (eStyleUnit_Auto == minHeight.GetUnit()) {
+    // In non-flexbox contexts, "min-height: auto" means "min-height: 0"
+    // XXXdholbert For flex items, we should set |minHeight| to the
+    // -moz-min-content keyword, instead of 0, once we support -moz-min-content
+    // as a height value.
+    minHeight.SetCoordValue(0);
+  }
+
+  SetValueToCoord(val, minHeight, true,
                   &nsComputedDOMStyle::GetCBContentHeight);
   return val;
 }

layout/style/nsRuleNode.cpp

@@ -6433,11 +6433,6 @@ nsRuleNode::ComputePositionData(void* aStartStruct,
            SETCOORD_LPOH | SETCOORD_INITIAL_NONE | SETCOORD_STORE_CALC,
            aContext, mPresContext, canStoreInRuleTree);
 
-  // Make 'auto' values for min-height compute to 0
-  if (pos->mMinHeight.GetUnit() == eStyleUnit_Auto) {
-    pos->mMinHeight.SetCoordValue(0);
-  }
-
   // box-sizing: enum, inherit, initial
   SetDiscrete(*aRuleData->ValueForBoxSizing(),
               pos->mBoxSizing, canStoreInRuleTree,

layout/style/nsStyleStruct.cpp

@@ -1133,7 +1133,7 @@ nsStylePosition::nsStylePosition(void)
   mMinWidth.SetAutoValue();
   mMaxWidth.SetNoneValue();
   mHeight.SetAutoValue();
-  mMinHeight.SetCoordValue(0);
+  mMinHeight.SetAutoValue();
   mMaxHeight.SetNoneValue();
 #ifdef MOZ_FLEXBOX
   mFlexBasis.SetAutoValue();

layout/style/nsStyleStruct.h

@@ -1142,7 +1142,13 @@ struct nsStylePosition {
   // FIXME: We should probably change the assumption to be the other way
   // around.
   bool HeightDependsOnContainer() const
-    { return HeightCoordDependsOnContainer(mHeight); }
+    {
+      return mHeight.GetUnit() == eStyleUnit_Auto || // CSS 2.1, 10.6.4, item (5)
+        HeightCoordDependsOnContainer(mHeight);
+    }
+
+  // NOTE: The comment above MinWidthDependsOnContainer about flex items
+  // applies here, too.
   bool MinHeightDependsOnContainer() const
     { return HeightCoordDependsOnContainer(mMinHeight); }
   bool MaxHeightDependsOnContainer() const
@@ -1156,10 +1162,7 @@ struct nsStylePosition {
 private:
   static bool WidthCoordDependsOnContainer(const nsStyleCoord &aCoord);
   static bool HeightCoordDependsOnContainer(const nsStyleCoord &aCoord)
-  {
-    return aCoord.GetUnit() == eStyleUnit_Auto || // CSS 2.1, 10.6.4, item (5)
-           aCoord.HasPercent();
-  }
+    { return aCoord.HasPercent(); }
 };
 
 struct nsStyleTextOverflowSide {