Problem:    Using freed memory with error in assert argument.
Solution:   Make a copy of the error.

Problem:    Invalid memory access when compiling :unlet.
Solution:   Don't read past the end of the line.

Problem:    Invalid memory access when compiling :lockvar.
Solution:   Don't read past the end of the line.

Problem:    'list' mode does not work properly with virtual text.
Solution:   Show the "$" at the right position. (closes #10913)

Problem:    Build error with small features.
Solution:   Add #ifdef.

Problem:    The override flag has no effect for virtual text. (Ben Jackson)
Solution:   Make the override flag work. (closes #10915)

Problem:    Stacktrace not shown when debugging.
Solution:   Set msg_scroll in msg_source(). (closes #10917)

Problem:    Redraw flags are not named specifically.
Solution:   Prefix "UPD_" to the flags, for UPDate_screen().

Problem:    Cursor in wrong position when inserting after virtual text. (Ben
            Jackson)
Solution:   Put the cursor after the virtual text, where the text will be
            inserted. (closes #10914)

Problem:    indexof() may leak memory.
Solution:   Free allocated values. (Yegappan Lakshmanan, closes #10916)