Bug 848539 part 4: Back out 82f73bdb2237, bug 763689 part 3 (style-system handling for min-height:auto). 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(4) load 266445-1.html # Bug 575011
+asserts(3) load 266445-1.html # Bug 575011
 load 268157-1.html
 load 269566-1.html
 load 272647-1.html

layout/base/nsLayoutUtils.cpp

@@ -2586,8 +2586,7 @@ GetPercentHeight(const nsStyleCoord& aStyle,
     if (minh > h)
       h = minh;
   } else {
-    NS_ASSERTION(pos->mMinHeight.HasPercent() ||
-                 pos->mMinHeight.GetUnit() == eStyleUnit_Auto,
+    NS_ASSERTION(pos->mMinHeight.HasPercent(),
                  "unknown min-height unit");
   }
 
@@ -2745,18 +2744,12 @@ 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_Auto || 
-          (styleMinHeight.GetUnit() == eStyleUnit_Coord &&
-           styleMinHeight.GetCoordValue() == 0)) ||
+        !(styleMinHeight.GetUnit() == eStyleUnit_Coord &&
+          styleMinHeight.GetCoordValue() == 0) ||
         styleMaxHeight.GetUnit() != eStyleUnit_None) {
 
       nsSize ratio = aFrame->GetIntrinsicRatio();

layout/generic/crashtests/crashtests.list

@@ -24,7 +24,7 @@ load 321224.xul
 load 322780-1.xul
 load 323381-1.html
 load 323381-2.html
-asserts-if(gtk2Widget,13-15) load 323386-1.html # Bug 575011
+asserts-if(gtk2Widget,14-15) load 323386-1.html # Bug 575011
 load 323389-1.html
 load 323389-2.html
 load 323493-1.html
@@ -330,7 +330,7 @@ load 495875-1.html
 load 495875-2.html
 load 499862-1.html
 load 499857-1.html
-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
+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
 load 501535-1.html
 load 503961-1.xhtml
 load 503961-2.html

layout/generic/nsHTMLReflowState.cpp

@@ -2537,13 +2537,8 @@ nsHTMLReflowState::ComputeMinMaxValues(nscoord aContainingBlockWidth,
   // 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
-  // flex container explicitly considers it.
   const nsStyleCoord &minHeight = mStylePosition->mMinHeight;
-  if (eStyleUnit_Auto == minHeight.GetUnit() ||
-      (NS_AUTOHEIGHT == aContainingBlockHeight &&
+  if ((NS_AUTOHEIGHT == aContainingBlockHeight &&
        minHeight.HasPercent()) ||
       (mFrameType == NS_CSS_FRAME_TYPE_INTERNAL_TABLE &&
        minHeight.IsCalcUnit() && minHeight.CalcHasPercent()) ||

layout/style/nsComputedDOMStyle.cpp

@@ -3409,17 +3409,7 @@ CSSValue*
 nsComputedDOMStyle::DoGetMinHeight()
 {
   nsROCSSPrimitiveValue *val = GetROCSSPrimitiveValue();
-  nsStyleCoord minHeight = StylePosition()->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,
+  SetValueToCoord(val, StylePosition()->mMinHeight, true,
                   &nsComputedDOMStyle::GetCBContentHeight);
   return val;
 }

layout/style/nsRuleNode.cpp

@@ -6493,6 +6493,11 @@ 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

@@ -1080,7 +1080,7 @@ nsStylePosition::nsStylePosition(void)
   mMinWidth.SetAutoValue();
   mMaxWidth.SetNoneValue();
   mHeight.SetAutoValue();
-  mMinHeight.SetAutoValue();
+  mMinHeight.SetCoordValue(0);
   mMaxHeight.SetNoneValue();
 #ifdef MOZ_FLEXBOX
   mFlexBasis.SetAutoValue();

layout/style/nsStyleStruct.h

@@ -1132,13 +1132,7 @@ struct nsStylePosition {
   // FIXME: We should probably change the assumption to be the other way
   // around.
   bool HeightDependsOnContainer() const
-    {
-      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.
+    { return HeightCoordDependsOnContainer(mHeight); }
   bool MinHeightDependsOnContainer() const
     { return HeightCoordDependsOnContainer(mMinHeight); }
   bool MaxHeightDependsOnContainer() const
@@ -1152,7 +1146,10 @@ struct nsStylePosition {
 private:
   static bool WidthCoordDependsOnContainer(const nsStyleCoord &aCoord);
   static bool HeightCoordDependsOnContainer(const nsStyleCoord &aCoord)
-    { return aCoord.HasPercent(); }
+  {
+    return aCoord.GetUnit() == eStyleUnit_Auto || // CSS 2.1, 10.6.4, item (5)
+           aCoord.HasPercent();
+  }
 };
 
 struct nsStyleTextOverflowSide {