On Tue, Jun 23, 2020 at 11:24:51AM -0400, Jeff King wrote:
> diff --git a/builtin/fast-export.c b/builtin/fast-export.c
> index 289395a131..4a3a4c933e 100644
> --- a/builtin/fast-export.c
> +++ b/builtin/fast-export.c
> @@ -387,16 +387,19 @@ static void *generate_fake_oid(const void *old, size_t *len)
> {
> static uint32_t counter = 1; /* avoid null oid */
> const unsigned hashsz = the_hash_algo->rawsz;
> - unsigned char *out = xcalloc(hashsz, 1);
> - put_be32(out + hashsz - 4, counter++);
> - return out;
> + struct object_id oid;
> + char *hex = xmallocz(GIT_MAX_HEXSZ);
> +
> + oidclr(&oid);
> + put_be32(oid.hash + hashsz - 4, counter++);
> + return oid_to_hex_r(hex, &oid);
> }
GCC 4.8 complains about this change in our CI job:
$ make CC=gcc-4.8 builtin/fast-export.o
CC builtin/fast-export.o
builtin/fast-export.c: In function ‘generate_fake_oid’:
builtin/fast-export.c:394:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
put_be32(oid.hash + hashsz - 4, counter++);
^
cc1: all warnings being treated as errors
