vim-patch:9.1.1443: potential buffer underflow in insertchar() (#34408)

Problem:  potential buffer underflow in insertchar()
Solution: verify that end_len is larger than zero
          (jinyaoguo)

When parsing the end-comment leader, end_len can be zero if
copy_option_part() writes no characters. The existing check
unconditionally accessed lead_end[end_len-1], causing potential
underflow when end_len == 0.

This change adds an end_len > 0 guard to ensure we only index lead_end
if there is at least one character.

closes: vim/vim#17476

https://github.com/vim/vim/commit/82a96e3dc0ee8f45bb0c1fe17a0cec1db7582e8f

Co-authored-by: jinyaoguo <guo846@purdue.edu>

0 files changed, 0 insertions, 0 deletions