Fix bidi reordering when part of text is rendered by fallback font

If the fallback font is used for part of a RTL text, we need to
position the different text items accordingly, subtracting the advance
instead of adding it.

Task-number: QTBUG-17117
Done-with: Lars

1 files changed, 13 insertions, 1 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index a4ab00ac31..604c1abe3c 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -6512,6 +6512,10 @@ void QPainter::drawTextItem(const QPointF &p, const QTextItem &_ti)
         qreal x = p.x();
         qreal y = p.y();
 
+        bool rtl = ti.flags & QTextItem::RightToLeft;
+        if (rtl)
+            x += ti.width.toReal();
+
         int start = 0;
         int end, i;
         for (end = 0; end < ti.glyphs.numGlyphs; ++end) {
@@ -6528,14 +6532,19 @@ void QPainter::drawTextItem(const QPointF &p, const QTextItem &_ti)
                 ti2.width += ti.glyphs.effectiveAdvance(i);
             }
 
+            if (rtl)
+                x -= ti2.width.toReal();
+
             d->engine->drawTextItem(QPointF(x, y), ti2);
 
+            if (!rtl)
+                x += ti2.width.toReal();
+
             // reset the high byte for all glyphs and advance to the next sub-string
             const int hi = which << 24;
             for (i = start; i < end; ++i) {
                 glyphs.glyphs[i] = hi | glyphs.glyphs[i];
             }
-            x += ti2.width.toReal();
 
             // change engine
             start = end;
@@ -6550,6 +6559,9 @@ void QPainter::drawTextItem(const QPointF &p, const QTextItem &_ti)
             ti2.width += ti.glyphs.effectiveAdvance(i);
         }
 
+        if (rtl)
+            x -= ti2.width.toReal();
+
         if (d->extended)
             d->extended->drawTextItem(QPointF(x, y), ti2);
         else