Fix bug QTBUG-4848

Make the shapeText function return numGlyphs properly - its not always
the same as length of string.

Task-number: QTBUG-4848
Reviewed-by: Rhys Weatherley

2 files changed, 14 insertions, 9 deletions

diff --git a/src/gui/text/qfontengine_mac.mm b/src/gui/text/qfontengine_mac.mm
index d11083fa2e..8ce437d4df 100644
--- a/src/gui/text/qfontengine_mac.mm
+++ b/src/gui/text/qfontengine_mac.mm
@@ -830,7 +830,6 @@ static OSStatus atsuPostLayoutCallback(ATSULayoutOperationSelector selector, ATS
             surrogates += (str[i].unicode() >= 0xd800 && str[i].unicode() < 0xdc00
                            && str[i+1].unicode() >= 0xdc00 && str[i+1].unicode() < 0xe000);
         }
-        Q_ASSERT(*nfo->numGlyphs == item->length - surrogates);
 #endif
         for (nextCharStop = item->from; nextCharStop < item->from + item->length; ++nextCharStop)
             if (item->charAttributes[nextCharStop].charStop)
@@ -856,10 +855,13 @@ static OSStatus atsuPostLayoutCallback(ATSULayoutOperationSelector selector, ATS
         QFixed xAdvance = FixedToQFixed(layoutData[glyphIdx + 1].realPos - layoutData[glyphIdx].realPos);
 
         if (glyphId != 0xffff || i == 0) {
-            nfo->glyphs->glyphs[i] = (glyphId & 0x00ffffff) | (fontIdx << 24);
+            if (i < nfo->glyphs->numGlyphs)
+            {
+                nfo->glyphs->glyphs[i] = (glyphId & 0x00ffffff) | (fontIdx << 24);
 
-            nfo->glyphs->advances_y[i] = yAdvance;
-            nfo->glyphs->advances_x[i] = xAdvance;
+                nfo->glyphs->advances_y[i] = yAdvance;
+                nfo->glyphs->advances_x[i] = xAdvance;
+            }
         } else {
             // ATSUI gives us 0xffff as glyph id at the index in the glyph array for
             // a character position that maps to a ligtature. Such a glyph id does not
@@ -1029,6 +1031,8 @@ bool QFontEngineMacMulti::stringToCMapInternal(const QChar *str, int len, QGlyph
     nfo.flags = flags;
     nfo.shaperItem = shaperItem;
 
+    int prevNumGlyphs = *nglyphs;
+
     QVarLengthArray<int> mappedFonts(len);
     for (int i = 0; i < len; ++i)
         mappedFonts[i] = 0;
@@ -1140,6 +1144,8 @@ bool QFontEngineMacMulti::stringToCMapInternal(const QChar *str, int len, QGlyph
     }
 
     ATSUClearLayoutCache(textLayout, kATSUFromTextBeginning);
+    if (prevNumGlyphs < *nfo.numGlyphs)
+        return false;
     return true;
 }
 
diff --git a/src/gui/text/qtextengine_mac.cpp b/src/gui/text/qtextengine_mac.cpp
index 4f20094303..e101830a81 100644
--- a/src/gui/text/qtextengine_mac.cpp
+++ b/src/gui/text/qtextengine_mac.cpp
@@ -50,7 +50,6 @@ static void heuristicSetGlyphAttributes(const QChar *uc, int length, QGlyphLayou
 {
     // ### zeroWidth and justification are missing here!!!!!
 
-    Q_ASSERT(num_glyphs <= length);
     Q_UNUSED(num_glyphs);
 
 //     qDebug("QScriptEngine::heuristicSetGlyphAttributes, num_glyphs=%d", item->num_glyphs);
@@ -596,7 +595,7 @@ void QTextEngine::shapeTextMac(int item) const
     }
 
     while (true) {
-	ensureSpace(num_glyphs);
+        ensureSpace(num_glyphs);
         num_glyphs = layoutData->glyphLayout.numGlyphs - layoutData->used;
 
         QGlyphLayout g = availableGlyphs(&si);
@@ -611,9 +610,9 @@ void QTextEngine::shapeTextMac(int item) const
                              log_clusters,
                              attributes())) {
 
-		heuristicSetGlyphAttributes(str, len, &g, log_clusters, num_glyphs);
-		break;
-	}
+            heuristicSetGlyphAttributes(str, len, &g, log_clusters, num_glyphs);
+            break;
+        }
     }
 
     si.num_glyphs = num_glyphs;