Avoid adding placeholder when deleting last text in root

Source/core/editing/DeleteSelectionCommand.cpp

Index: Source/core/editing/DeleteSelectionCommand.cpp
diff --git a/Source/core/editing/DeleteSelectionCommand.cpp b/Source/core/editing/DeleteSelectionCommand.cpp
index d407b7d2856e22c2a7c14eb30a6f2064a021ba73..1e4bdd0ee2e1da8888f493f07cc149047696957f 100644
--- a/Source/core/editing/DeleteSelectionCommand.cpp
+++ b/Source/core/editing/DeleteSelectionCommand.cpp
@@ -802,9 +802,12 @@ void DeleteSelectionCommand::doApply()
     EAffinity affinity = m_selectionToDelete.affinity();
     
     Position downstreamEnd = m_selectionToDelete.end().downstream();
-    m_needPlaceholder = isStartOfParagraph(m_selectionToDelete.visibleStart(), CanCrossEditingBoundary)
-            && isEndOfParagraph(m_selectionToDelete.visibleEnd(), CanCrossEditingBoundary)
-            && !lineBreakExistsAtVisiblePosition(m_selectionToDelete.visibleEnd());
+    bool rootWillStayOpenWithoutPlaceholder = downstreamEnd.containerNode()->isTextNode()

[ojan, 2013/05/10 23:38:21]

Actually, now that I look at this more closely, why does the containerNode need
to be a textNode? One if you are deleting the last image in a contentEditable?

+        && downstreamEnd.containerNode()->parentNode() == downstreamEnd.containerNode()->rootEditableElement();
+    m_needPlaceholder = !rootWillStayOpenWithoutPlaceholder
+        && isStartOfParagraph(m_selectionToDelete.visibleStart(), CanCrossEditingBoundary)
+        && isEndOfParagraph(m_selectionToDelete.visibleEnd(), CanCrossEditingBoundary)
+        && !lineBreakExistsAtVisiblePosition(m_selectionToDelete.visibleEnd());
     if (m_needPlaceholder) {
         // Don't need a placeholder when deleting a selection that starts just before a table
         // and ends inside it (we do need placeholders to hold open empty cells, but that's