[2/2] richedit: Don't change text mode with undo or redo stack.

[Dylan Smith]

---
MSDN recommends WM_SETTEXT be used with empty text before calling
EM_SETTEXTMODE which clears the undo and redo stack. I found out
clearing the undo stack is necessary to change the text mode.
---
 dlls/riched20/editor.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/dlls/riched20/editor.c b/dlls/riched20/editor.c
index a6ca2b8..842b159 100644
--- a/dlls/riched20/editor.c
+++ b/dlls/riched20/editor.c
@@ -4319,7 +4319,7 @@ LRESULT ME_HandleMessage(ME_TextEditor *editor, UINT msg, WPARAM wParam,
     int mask = 0;
     int changes = 0;
 
-    if (ME_GetTextLength(editor))
+    if (ME_GetTextLength(editor) || editor->pUndoStack || editor->pRedoStack)
       return E_UNEXPECTED;
 
     /* Check for mutually exclusive flags in adjacent bits of wParam */
-- 
1.7.0.4