Bug 406299. Make sure we include the font ascent/descent of a soft hyphen if there is one (gfx bits). r+sr=dbaron

gfx/thebes/public/gfxFont.h

@@ -521,19 +521,13 @@ public:
     /**
      * Metrics for a particular string
      */
-    struct RunMetrics {
+    struct THEBES_API RunMetrics {
         RunMetrics() {
             mAdvanceWidth = mAscent = mDescent = 0.0;
             mBoundingBox = gfxRect(0,0,0,0);
         }
 
-        void CombineWith(const RunMetrics& aOtherOnRight) {
-            mAscent = PR_MAX(mAscent, aOtherOnRight.mAscent);
-            mDescent = PR_MAX(mDescent, aOtherOnRight.mDescent);
-            mBoundingBox =
-                mBoundingBox.Union(aOtherOnRight.mBoundingBox + gfxPoint(mAdvanceWidth, 0));
-            mAdvanceWidth += aOtherOnRight.mAdvanceWidth;
-        }
+        void CombineWith(const RunMetrics& aOther, PRBool aOtherIsOnLeft);
 
         // can be negative (partly due to negative spacing).
         // Advance widths should be additive: the advance width of the

gfx/thebes/src/gfxFont.cpp

@@ -246,6 +246,21 @@ gfxFontCache::DestroyFont(gfxFont *aFont)
     delete aFont;
 }
 
+void
+gfxFont::RunMetrics::CombineWith(const RunMetrics& aOther, PRBool aOtherIsOnLeft)
+{
+    mAscent = PR_MAX(mAscent, aOther.mAscent);
+    mDescent = PR_MAX(mDescent, aOther.mDescent);
+    if (aOtherIsOnLeft) {
+        mBoundingBox =
+            (mBoundingBox + gfxPoint(aOther.mAdvanceWidth, 0)).Union(aOther.mBoundingBox);
+    } else {
+        mBoundingBox =
+            mBoundingBox.Union(aOther.mBoundingBox + gfxPoint(mAdvanceWidth, 0));
+    }
+    mAdvanceWidth += aOther.mAdvanceWidth;
+}
+
 gfxFont::gfxFont(gfxFontEntry *aFontEntry, const gfxFontStyle *aFontStyle) :
     mIsValid(PR_TRUE), mStyle(*aFontStyle), mFontEntry(aFontEntry), mSyntheticBoldOffset(0)
 {
@@ -1753,7 +1768,6 @@ gfxTextRun::DrawToPath(gfxContext *aContext, gfxPoint aPt,
     }
 }
 
-
 void
 gfxTextRun::AccumulateMetricsForRun(gfxFont *aFont,
                                     PRUint32 aStart, PRUint32 aEnd,
@@ -1767,13 +1781,7 @@ gfxTextRun::AccumulateMetricsForRun(gfxFont *aFont,
         aSpacingStart, aSpacingEnd, &spacingBuffer);
     Metrics metrics = aFont->Measure(this, aStart, aEnd, aTight, aRefContext,
                                      haveSpacing ? spacingBuffer.Elements() : nsnull);
- 
-    if (IsRightToLeft()) {
-        metrics.CombineWith(*aMetrics);
-        *aMetrics = metrics;
-    } else {
-        aMetrics->CombineWith(metrics);
-    }
+    aMetrics->CombineWith(metrics, IsRightToLeft());
 }
 
 void
@@ -1809,12 +1817,7 @@ gfxTextRun::AccumulatePartialLigatureMetrics(gfxFont *aFont,
             : data.mPartAdvance;    
     metrics.mAdvanceWidth = data.mPartWidth;
 
-    if (IsRightToLeft()) {
-        metrics.CombineWith(*aMetrics);
-        *aMetrics = metrics;
-    } else {
-        aMetrics->CombineWith(metrics);
-    }
+    aMetrics->CombineWith(metrics, IsRightToLeft());
 }
 
 gfxTextRun::Metrics