Re: [PATCH v2 3/3] Use the newly-introduced regexec_buf() function

> The new regexec_buf() function operates on buffers with an explicitly
> specified length, rather than NUL-terminated strings.
> 
> We need to use this function whenever the buffer we want to pass to
> regexec() may have been mmap()ed (and is hence not NUL-terminated).
> 
> Note: the original motivation for this patch was to fix a bug where
> `git diff -G <regex>` would crash. This patch converts more callers,
> though, some of which explicitly allocated and constructed
> NUL-terminated strings (or worse: modified read-only buffers to insert
> NULs).
> 
> Some of the buffers actually may be NUL-terminated. As regexec_buf()
> uses REG_STARTEND where available, but has to fall back to allocating
> and constructing NUL-terminated strings where REG_STARTEND is not
> available, this makes the code less efficient in the latter case.
> 
> However, given the widespread support for REG_STARTEND, combined with
> the improved ease of code maintenance, we strike the balance in favor
> of REG_STARTEND.
> 
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>  diff.c             |  3 ++-
>  diffcore-pickaxe.c | 18 ++++++++----------
>  xdiff-interface.c  | 13 ++++---------
>  3 files changed, 14 insertions(+), 20 deletions(-)