[PATCH 2/4] index-pack: use size_t in write_compressed()

write_compressed() in builtin/index-pack.c takes the object size as an
"unsigned int" and returns an "int", which are 32 bits wide on all
platforms. It is used by append_obj_to_pack() when resolving thin packs
with --fix-thin.

With a local base of 4GiB or more, write_compressed() compresses only
the first "size mod 2^32" bytes, while the pack header written by
append_obj_to_pack() records the full size. Later, when resolving deltas
against that base, unpack_data() encounters an early end of stream and
dies with "serious inflate inconsistency". Shrinking the parameter to 16
bits and using a 100KiB base makes "git index-pack --fix-thin" die the
same way.

Use size_t for both the size parameter and the return value.

Triggering this requires processing a local base of 4GiB or more, so
no test is added.

Signed-off-by: Elia Pinto <redacted>
---
 builtin/index-pack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 0264c18c5f..f65228468b 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c

@@ -1411,7 +1411,7 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha
 		    nr_ofs_deltas + nr_ref_deltas - nr_resolved_deltas);
 }
 
-static int write_compressed(struct hashfile *f, void *in, unsigned int size)
+static size_t write_compressed(struct hashfile *f, void *in, size_t size)
 {
 	git_zstream stream;
 	int status;

-- 
2.53.0