ValueError if searching for undo history which has a null character ^@

[ruohola]

The error occurs when you're trying to search (with /) a place in the undo history which also happens to have a ^@ aka null character in one of the changed lines. The place of the null character on the line is irrelevant, it just has to be somewhere in a + or - line.

The error is easy to reproduce:

• Start editing a new file
• Type the line (use CTRL-V CTRL-J, for typing the ^@): test^@
• Exit insert mode so the changes are in different undos:
• Make a 2nd line with the text: otherline
• Open Mundo and /test
• This error happens:

Error detected while processing function <SNR>54_MundoPython:
line    1:
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/eero/.dotfiles/vim/plugged/vim-mundo/autoload/mundo.py", line 306, in MundoSearch
    MundoNextMatch()
  File "/Users/eero/.dotfiles/vim/plugged/vim-mundo/autoload/mundo.py", line 314, in MundoNextMatch
    MundoMatch(1)
  File "/Users/eero/.dotfiles/vim/plugged/vim-mundo/autoload/mundo.py", line 344, in MundoMatch
    match_index = vim.eval('match("%s",@/)'% change.replace("\\","\\\\").replace('"','\\"'))
ValueError: embedded null byte