BidiResolver should not try to reverse runs when the run count is zero

Source/core/platform/text/BidiResolver.h

Index: Source/core/platform/text/BidiResolver.h
diff --git a/Source/core/platform/text/BidiResolver.h b/Source/core/platform/text/BidiResolver.h
index 435612ec3bee7ca6e563d3098f0f080128d7ceb6..a287dcfcd3e9456135569fb1522deca88a60b1f0 100644
--- a/Source/core/platform/text/BidiResolver.h
+++ b/Source/core/platform/text/BidiResolver.h
@@ -574,7 +574,7 @@ void BidiResolver<Iterator, Run>::createBidiRunsForLine(const Iterator& end, Vis
         m_direction = override == VisualLeftToRightOverride ? LeftToRight : RightToLeft;
         appendRun();
         m_runs.setLogicallyLastRun(m_runs.lastRun());
-        if (override == VisualRightToLeftOverride)
+        if (override == VisualRightToLeftOverride && m_runs.runCount())
             m_runs.reverseRuns(0, m_runs.runCount() - 1);

[eseidel, 2013/10/02 17:28:11]

Do we ever call this w/o the full length?  If not we could just remove the
parameters.

         return;
     }