vim-patch:9.1.0399: block_editing errors out when using del (#28867)

Problem:  block_editing errors out when using del
          (@Jamarley)
Solution: Change ins_len from size_t to int and
          properly check that it doesn't become negative

There is a check in os.c that verifies that `ins_len` does not become
negative:
```
if (pre_textlen >= 0 && (ins_len = len - pre_textlen - offset) > 0)
```
However this only works, if ins_len can actually become negative and
unfortunately, ins_len has been declared as `size_t` so instead of
becoming negative it will wrap around and be very large.

So let's define it as integer, after which the condition above
properly catches this condition.

fixes: vim/vim#14734
closes: vim/vim#14735

https://github.com/vim/vim/commit/d5c8c0920e1eee9ff7a9fa5168d8e85c01670630

Co-authored-by: Christian Brabandt <cb@256bit.org>

0 files changed, 0 insertions, 0 deletions