Handle border-image with fill and zero-width borders

Source/core/style/ComputedStyle.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 372 matching lines @@
 
     void setAffectedByFocus() { noninherited_flags.affectedByFocus = true; }
     void setAffectedByHover() { noninherited_flags.affectedByHover = true; }
     void setAffectedByActive() { noninherited_flags.affectedByActive = true; }
     void setAffectedByDrag() { noninherited_flags.affectedByDrag = true; }
 
     bool operator==(const ComputedStyle& other) const;
     bool operator!=(const ComputedStyle& other) const { return !(*this == other); }
     bool isFloating() const { return noninherited_flags.floating != NoFloat; }
     bool hasMargin() const { return surround->margin.nonZero(); }
+    bool hasBorderFill() const { return surround->border.hasBorderFill(); }
     bool hasBorder() const { return surround->border.hasBorder(); }
+    bool hasBorderDecoration() const { return hasBorder() || hasBorderFill(); }

[pdr., 2015/06/02 03:07:56]

Can the hasBorder and image check in ComputedStyle::borderObscuresBackground be
replaced with hasBorderDecoration?

[davve, 2015/06/03 06:56:01]

You mean replacing

    if (!hasBorder())
        return false;

    // Bail if we have any border-image for now. We could look at the image
alpha to improve this.
    if (borderImage().image())
        return false;

    ...

with:

    if (!hasBorderDecoration())
        return false;

    ...

Such a change would mean that we would go on to inspect edges for the
case when all border widths are zero but there still is a border-image
to draw. Since we don't inspect the alpha channel of the border-image,
I think border-image should mean we always bail.

     bool hasPadding() const { return surround->padding.nonZero(); }
     bool hasMarginBeforeQuirk() const { return marginBefore().quirk(); }
     bool hasMarginAfterQuirk() const { return marginAfter().quirk(); }
 
     bool hasBackgroundImage() const { return m_background->background().hasImage(); }
     bool hasFixedBackgroundImage() const { return m_background->background().hasFixedImage(); }
 
     bool hasEntirelyFixedBackground() const;
 
     bool hasAppearance() const { return appearance() != NoControlPart; }
@@ skipping 1101 matching lines @@
     void setEmptyState(bool b) { setUnique(); noninherited_flags.emptyState = b; }
 
     Color visitedDependentColor(int colorProperty) const;
 
     void setHasExplicitlyInheritedProperties() { noninherited_flags.explicitInheritance = true; }
     bool hasExplicitlyInheritedProperties() const { return noninherited_flags.explicitInheritance; }
 
     bool hasChildDependentFlags() const { return emptyState() || hasExplicitlyInheritedProperties(); }
     void copyChildDependentFlagsFrom(const ComputedStyle&);
 
-    bool hasBoxDecorations() const { return hasBorder() || hasBorderRadius() || hasOutline() || hasAppearance() || boxShadow() || hasFilter() || resize() != RESIZE_NONE; }
+    bool hasBoxDecorations() const { return hasBorderDecoration() || hasBorderRadius() || hasOutline() || hasAppearance() || boxShadow() || hasFilter() || resize() != RESIZE_NONE; }
 
     bool borderObscuresBackground() const;
     void getBorderEdgeInfo(BorderEdge edges[], bool includeLogicalLeftEdge = true, bool includeLogicalRightEdge = true) const;
 
     // Initial values for all the properties
     static EBorderCollapse initialBorderCollapse() { return BSEPARATE; }
     static EBorderStyle initialBorderStyle() { return BNONE; }
     static OutlineIsAuto initialOutlineStyleIsAuto() { return AUTO_OFF; }
     static NinePieceImage initialNinePieceImage() { return NinePieceImage(); }
     static LengthSize initialBorderRadius() { return LengthSize(Length(0, Fixed), Length(0, Fixed)); }
@@ skipping 355 matching lines @@
 }
 
 inline bool ComputedStyle::hasPseudoElementStyle() const
 {
     return noninherited_flags.pseudoBits & PSEUDO_ELEMENT_MASK;
 }
 
 } // namespace blink
 
 #endif // ComputedStyle_h