Bug 1149009 - Suppress line break inside text frame if it is directly contained by ruby content box. r=dbaron

layout/base/nsBidiPresUtils.cpp

@@ -1055,7 +1055,8 @@ nsBidiPresUtils::TraverseFrames(nsBlockFrame*              aBlockFrame,
       if (nsGkAtoms::textFrame == frameType) {
         if (content != aBpd->mPrevContent) {
           aBpd->mPrevContent = content;
-          if (!frame->StyleText()->NewlineIsSignificant(frame)) {
+          if (!frame->StyleText()->NewlineIsSignificant(
+                static_cast<nsTextFrame*>(frame))) {
             content->AppendTextTo(aBpd->mBuffer);
           } else {
             /*

layout/generic/nsTextFrame.cpp

@@ -678,7 +678,7 @@ static bool IsSpaceCombiningSequenceTail(const nsTextFragment* aFrag, uint32_t a
 // Check whether aPos is a space for CSS 'word-spacing' purposes
 static bool
 IsCSSWordSpacingSpace(const nsTextFragment* aFrag, uint32_t aPos,
-                      nsIFrame* aFrame, const nsStyleText* aStyleText)
+                      nsTextFrame* aFrame, const nsStyleText* aStyleText)
 {
   NS_ASSERTION(aPos < aFrag->GetLength(), "No text for IsSpace!");
 
@@ -1942,7 +1942,7 @@ BuildTextRunsScanner::BuildTextRunForFrames(void* aTextBuffer)
     textFlags |= GetSpacingFlags(WordSpacing(f));
     nsTextFrameUtils::CompressionMode compression =
       GetCSSWhitespaceToCompressionMode(f, textStyle);
-    if ((enabledJustification || f->StyleContext()->ShouldSuppressLineBreak()) &&
+    if ((enabledJustification || f->ShouldSuppressLineBreak()) &&
         !textStyle->WhiteSpaceIsSignificant() && !isSVG) {
       textFlags |= gfxTextRunFactory::TEXT_ENABLE_SPACING;
     }
@@ -2816,9 +2816,9 @@ static int32_t FindChar(const nsTextFragment* frag,
   return -1;
 }
 
-static bool IsChineseOrJapanese(nsIFrame* aFrame)
+static bool IsChineseOrJapanese(nsTextFrame* aFrame)
 {
-  if (aFrame->StyleContext()->ShouldSuppressLineBreak()) {
+  if (aFrame->ShouldSuppressLineBreak()) {
     // Always treat ruby as CJ language so that those characters can
     // be expanded properly even when surrounded by other language.
     return true;
@@ -8343,7 +8343,7 @@ nsTextFrame::ReflowText(nsLineLayout& aLineLayout, nscoord aAvailableWidth,
                                    (GetStateBits() & TEXT_IS_IN_TOKEN_MATHML);
   gfxBreakPriority breakPriority = aLineLayout.LastOptionalBreakPriority();
   gfxTextRun::SuppressBreak suppressBreak = gfxTextRun::eNoSuppressBreak;
-  if (StyleContext()->ShouldSuppressLineBreak()) {
+  if (ShouldSuppressLineBreak()) {
     suppressBreak = gfxTextRun::eSuppressAllBreaks;
   } else if (!aLineLayout.LineIsBreakable()) {
     suppressBreak = gfxTextRun::eSuppressInitialBreak;
@@ -8552,7 +8552,7 @@ nsTextFrame::ReflowText(nsLineLayout& aLineLayout, nscoord aAvailableWidth,
   bool emptyTextAtStartOfLine = atStartOfLine && length == 0;
   if (!breakAfter && charsFit == length && !emptyTextAtStartOfLine &&
       transformedOffset + transformedLength == mTextRun->GetLength() &&
-      !StyleContext()->ShouldSuppressLineBreak() &&
+      !ShouldSuppressLineBreak() &&
       (mTextRun->GetFlags() & nsTextFrameUtils::TEXT_HAS_TRAILING_BREAK)) {
     // We placed all the text in the textrun and we have a break opportunity at
     // the end of the textrun. We need to record it because the following
@@ -8614,7 +8614,7 @@ nsTextFrame::ReflowText(nsLineLayout& aLineLayout, nscoord aAvailableWidth,
   if (!textStyle->WhiteSpaceIsSignificant() &&
       (lineContainer->StyleText()->mTextAlign == NS_STYLE_TEXT_ALIGN_JUSTIFY ||
        lineContainer->StyleText()->mTextAlignLast == NS_STYLE_TEXT_ALIGN_JUSTIFY ||
-       StyleContext()->ShouldSuppressLineBreak()) &&
+       ShouldSuppressLineBreak()) &&
       !lineContainer->IsSVGText()) {
     AddStateBits(TEXT_JUSTIFICATION_ENABLED);
     provider.ComputeJustification(offset, charsFit);

layout/generic/nsTextFrame.h

@@ -15,6 +15,7 @@
 #include "gfxTextRun.h"
 #include "nsDisplayList.h"
 #include "JustificationUtils.h"
+#include "RubyUtils.h"
 
 // Undo the windows.h damage
 #if defined(XP_WIN) && defined(DrawText)
@@ -122,6 +123,18 @@ public:
                                              nsIFrame::eLineParticipant));
   }
 
+  bool ShouldSuppressLineBreak() const
+  {
+    // If the parent frame of the text frame is ruby content box, it must
+    // suppress line break inside. This check is necessary, because when
+    // a whitespace is only contained by pseudo ruby frames, its style
+    // context won't have SuppressLineBreak bit set.
+    if (mozilla::RubyUtils::IsRubyContentBox(GetParent()->GetType())) {
+      return true;
+    }
+    return StyleContext()->ShouldSuppressLineBreak();
+  }
+
   virtual void InvalidateFrame(uint32_t aDisplayItemKey = 0) override;
   virtual void InvalidateFrameWithRect(const nsRect& aRect, uint32_t aDisplayItemKey = 0) override;
 

layout/reftests/css-ruby/line-break-suppression-4-ref.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Bug 1149009 - Line break suppression on whitespaces wrapped but not contained in ruby boxes</title>
+</head>
+<body>
+  <span style="white-space: pre"><rb>a</rb><rb>
+</rb><rb>b</rb></span>
+</body>
+</html>

layout/reftests/css-ruby/line-break-suppression-4.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Bug 1149009 - Line break suppression on whitespaces wrapped but not contained in ruby boxes</title>
+</head>
+<body>
+  <span style="white-space: pre"><rb>a</rb>
+<rb>b</rb></span>
+</body>
+</html>

layout/reftests/css-ruby/reftest.list

@@ -31,6 +31,7 @@ fuzzy-if(winWidget,255,792) == lang-specific-style-1.html lang-specific-style-1-
 == line-break-suppression-1.html line-break-suppression-1-ref.html
 == line-break-suppression-2.html line-break-suppression-2-ref.html
 == line-break-suppression-3.html line-break-suppression-3-ref.html
+== line-break-suppression-4.html line-break-suppression-4-ref.html
 == line-height-1.html line-height-1-ref.html
 == line-height-2.html line-height-2-ref.html
 == line-height-3.html line-height-3-ref.html

layout/style/nsStyleContext.h

@@ -157,6 +157,8 @@ public:
   // as if nowrap is set, <br> is suppressed, and blocks are inlinized.
   // This bit is propogated to all children of line partitipants. It is
   // currently used by ruby to make its content frames unbreakable.
+  // NOTE: for nsTextFrame, use nsTextFrame::ShouldSuppressLineBreak()
+  // instead of this method.
   bool ShouldSuppressLineBreak() const
     { return !!(mBits & NS_STYLE_SUPPRESS_LINEBREAK); }
 

layout/style/nsStyleStruct.h

@@ -30,6 +30,7 @@
 #include "CounterStyleManager.h"
 
 class nsIFrame;
+class nsTextFrame;
 class nsIURI;
 class imgIContainer;
 
@@ -1666,7 +1667,7 @@ struct nsStyleText {
   // style struct is for.  If the frame is for SVG text or inside ruby,
   // the return value will be massaged to be something that makes sense
   // for those cases.
-  inline bool NewlineIsSignificant(const nsIFrame* aContextFrame) const;
+  inline bool NewlineIsSignificant(const nsTextFrame* aContextFrame) const;
   inline bool WhiteSpaceCanWrap(const nsIFrame* aContextFrame) const;
   inline bool WordCanWrap(const nsIFrame* aContextFrame) const;
 };

layout/style/nsStyleStructInlines.h

@@ -14,6 +14,7 @@
 #include "nsIFrame.h"
 #include "nsStyleStruct.h"
 #include "nsIContent.h" // for GetParent()
+#include "nsTextFrame.h" // for nsTextFrame::ShouldSuppressLineBreak
 
 inline void
 nsStyleImage::SetSubImage(uint8_t aIndex, imgIContainer* aSubImage) const
@@ -43,11 +44,11 @@ nsStyleText::GetTextShadow() const
 }
 
 bool
-nsStyleText::NewlineIsSignificant(const nsIFrame* aContextFrame) const
+nsStyleText::NewlineIsSignificant(const nsTextFrame* aContextFrame) const
 {
   NS_ASSERTION(aContextFrame->StyleText() == this, "unexpected aContextFrame");
   return NewlineIsSignificantStyle() &&
-    !aContextFrame->StyleContext()->ShouldSuppressLineBreak();
+    !aContextFrame->ShouldSuppressLineBreak();
 }
 
 bool