Re: [PATCH 0/5] const-correctness in grep.c

Jeff King [off-list ref] writes:

While discussing [1], I noticed that the grep code mostly takes
non-const buffers, even though it is conceptually a read-only operation
to search in them. The culprit is a handful of spots that temporarily
tie off NUL-terminated strings by overwriting a byte of the buffer and
then restoring it. But I think we no longer need to do so these days,
now that we have a regexec_buf() that can take a ptr/size pair.

Yes, the haystack has not been read-only exactly because we didn't
have <ptr,size> based regexec variant when the grep machinery was
written, and there is no reason why we want to use the "temporarily
terminate by swapping the byte with a NUL" trick.

It always is a pleasure to read such a concise and to-the-point
summary.  With a clear summary like that, a reader almost does not
have to see the patch to guess how the rest of the story goes ;-)