From 753c8101b027f34359a921a8acb3abe7f10058c5 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Thu, 19 Mar 2026 00:15:59 -0700 Subject: [PATCH] rerere: update to modern representation of empty strbufs Back when b4833a2c (rerere: Fix use of an empty strbuf.buf, 2007-09-26) was written, a freshly initialized empty strbuf had NULL in its .buf member, with .len set to 0. The code this patch touches in rerere.c was written to _fix_ the original code that assumed that the .buf member is always pointing at a NUL-terminated string, even for an empty string, which did not hold back then. That changed in b315c5c0 (strbuf change: be sure ->buf is never ever NULL., 2007-09-27), and it has again become safe to assume that .buf is never NULL, and .buf[0] has '\0' for an empty string (i.e., a strbuf with its .len member set to 0). A funny thing is, this piece of code has been moved around from builtin-rerere.c to rerere.c and also adjusted for updates to the hash function API over the years, but nobody bothered to question if this special casing for an empty strbuf was still necessary: b4833a2c62 (rerere: Fix use of an empty strbuf.buf, 2007-09-26) 5b2fd95606 (rerere: Separate libgit and builtin functions, 2008-07-09) 9126f0091f (fix openssl headers conflicting with custom SHA1 implementations, 2008-10-01) c0f16f8e14 (rerere: factor out handle_conflict function, 2018-08-05) 0d7c419a94 (rerere: convert to use the_hash_algo, 2018-10-15) 0578f1e66a (global: adapt callers to use generic hash context helpers, 2025-01-31) Finally get rid of the special casing that was unnecessary for the last 19 years. Signed-off-by: Junio C Hamano --- rerere.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/rerere.c b/rerere.c index 3cd37c5f0a..6e0c218332 100644 --- a/rerere.c +++ b/rerere.c @@ -402,12 +402,8 @@ static int handle_conflict(struct strbuf *out, struct rerere_io *io, strbuf_addbuf(out, &two); rerere_strbuf_putconflict(out, '>', marker_size); if (ctx) { - git_hash_update(ctx, one.buf ? - one.buf : "", - one.len + 1); - git_hash_update(ctx, two.buf ? - two.buf : "", - two.len + 1); + git_hash_update(ctx, one.buf, one.len + 1); + git_hash_update(ctx, two.buf, two.len + 1); } break; } else if (hunk == RR_SIDE_1) -- 2.52.0