The count `strlen()` in
```vim
line = printf(indent_start .. substitute(cms, '%s\@!', '%%', 'g'),
strpart(getline(lnum), strlen(indent_start)))
```
is too large if the block of lines to be operated on contains different
whitespace indenting (tab vs. spaces).
Considering using `2gcc` on the first line with 4 spaces as indenting
and on the next line using a single tab character (with &tabstop value
of 8):
Using `strlen(indent_start) = 4` for an initial indent of 4 spaces is
correct for the first line, but wrong for the next line and will
therefore wrongly comment out the tab-indented line (and possibly
deleting some content).
The new check is still too simple because it assumes that as soon as
there's a tab the whole indent is made of tabs; it's a start of entering
the mixed tab and whitespace indent rabbit hole.
fixes: #15797closes: #15805
Signed-off-by: Konfekt <Konfekt@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
