[Bug 7144] New: richedit assert when doing an undo or redo

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=7144

Summary: richedit assert when doing an undo or redo
           Product: Wine
           Version: 0.9.29.
          Platform: Other
        OS/Version: other
            Status: NEW
          Severity: critical
          Priority: P2
         Component: wine-richedit
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

This is reproducable in wordpad that comes with wine.
type "sometext\n"  using an actual return instead of '\n'.
select all the text by putting the cursor before 's' and move the mouse down one
line.  hit ctrl-c.  put the cursor on the line below "sometext".  hit ctrl-v.
then hit ctrl-z to undo, and an assert will be hit.

para.c:208: ME_JoinParagraphs: Assertion `tp->member.para.next_para->type ==
diParagraph' failed.

here's another way to hit an assert:
type "some text\n\nsome text"  (again, real returns instead of '\n')
select "text" from the first line, and ctrl-c, to put it on the clipboard.
put the cursor on the empyt second line.  hit ctrl-v to paste.  hit ctrl-z to
undo it (notice how the undo was incorrect).  hit ctrl-z again, and nothing
happens.  hit ctrl-y to redo, and we hit an assert.
undo.c:180: ME_PlayUndoItem: Assertion `0' failed.