Subject: [PATCH v3 16/17] chunk-format: restore duplicate chunk checks

From: "Derrick Stolee via GitGitGadget" <[email-masked]>
Date: Fri, 05 Feb 2021 14:30:51 +0000

From: Derrick Stolee <[email-masked]>

Before refactoring into the chunk-format API, the commit-graph parsing
logic included checks for duplicate chunks. It is unlikely that we would
desire a chunk-based file format that allows duplicate chunk IDs in the
table of contents, so add duplicate checks into
read_table_of_contents().

Signed-off-by: Derrick Stolee <[email-masked]>
---
 chunk-format.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/chunk-format.c b/chunk-format.c
index bc9d4caf7276..e4889d9efcd1 100644
--- a/chunk-format.c
+++ b/chunk-format.c
@@ -98,6 +98,7 @@ int read_table_of_contents(struct chunkfile *cf,
 			   uint64_t toc_offset,
 			   int toc_length)
 {
+	int i;
 	uint32_t chunk_id;
 	const unsigned char *table_of_contents = mfile + toc_offset;
 
@@ -124,6 +125,14 @@ int read_table_of_contents(struct chunkfile *cf,
 			return -1;
 		}
 
+		for (i = 0; i < cf->chunks_nr; i++) {
+			if (cf->chunks[i].id == chunk_id) {
+				error(_("duplicate chunk ID %"PRIx32" found"),
+					chunk_id);
+				return -1;
+			}
+		}
+
 		cf->chunks[cf->chunks_nr].id = chunk_id;
 		cf->chunks[cf->chunks_nr].start = mfile + chunk_offset;
 		cf->chunks[cf->chunks_nr].size = next_chunk_offset - chunk_offset;
-- 
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