Subject: [PATCH 15/17] midx: use 64-bit multiplication for chunk sizes

From: "Derrick Stolee via GitGitGadget" <[email-masked]>
Date: Tue, 26 Jan 2021 16:01:24 +0000

From: Derrick Stolee <[email-masked]>

When calculating the sizes of certain chunks, we should use 64-bit
multiplication always. This allows us to properly predict the chunk
sizes without risk of overflow.

Signed-off-by: Derrick Stolee <[email-masked]>
---
 midx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/midx.c b/midx.c
index dd019c00795..47aaeb804b8 100644
--- a/midx.c
+++ b/midx.c
@@ -945,7 +945,7 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index *
 	add_chunk(cf, MIDX_CHUNKID_OIDFANOUT,
 		  write_midx_oid_fanout, MIDX_CHUNK_FANOUT_SIZE);
 	add_chunk(cf, MIDX_CHUNKID_OIDLOOKUP,
-		  write_midx_oid_lookup, ctx.entries_nr * the_hash_algo->rawsz);
+		  write_midx_oid_lookup, (uint64_t)ctx.entries_nr * the_hash_algo->rawsz);
 	add_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS,
 		  write_midx_object_offsets,
 		  ctx.entries_nr * MIDX_CHUNK_OFFSET_WIDTH);
@@ -953,7 +953,7 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index *
 	if (ctx.large_offsets_needed)
 		add_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS,
 			write_midx_large_offsets,
-			ctx.num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH);
+			(uint64_t)ctx.num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH);
 
 	write_midx_header(f, get_num_chunks(cf), ctx.nr - dropped_packs);
 	write_chunkfile(cf, &ctx);
-- 
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