Merge 129814 - REGRESSION(r129186): Pressing enter at the end of a line deletes the line

Source/WebCore/rendering/RenderText.cpp

Index: Source/WebCore/rendering/RenderText.cpp
===================================================================
--- Source/WebCore/rendering/RenderText.cpp	(revision 129817)
+++ Source/WebCore/rendering/RenderText.cpp	(working copy)
@@ -1253,6 +1253,9 @@
 
 void RenderText::setTextWithOffset(PassRefPtr<StringImpl> text, unsigned offset, unsigned len, bool force)
 {
+    if (!force && equal(m_text.impl(), text.get()))
+        return;
+
     unsigned oldLen = textLength();
     unsigned newLen = text->length();
     int delta = newLen - oldLen;
@@ -1324,7 +1327,7 @@
     }
 
     m_linesDirty = dirtiedLines;
-    setText(text, force);
+    setText(text, force || dirtiedLines);
 }
 
 void RenderText::transformText()