[PATCH v4 16/17] chunk-format: restore duplicate chunk checks

From: Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
Date: Feb 18, 2021, 14:07 UTC
Message-ID: <0e58218be4185b428aec48a9169134517330bcde.1613657260.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.848.v4.git.1613657259.gitgitgadget@gmail.com>

From: Derrick Stolee <dstolee@microsoft.com>

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 <dstolee@microsoft.com>
---
 chunk-format.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/chunk-format.c b/chunk-format.c
index 2c1fecf1c3e5..da191e59a29d 100644
--- a/chunk-format.c
+++ b/chunk-format.c
@@ -97,6 +97,7 @@ 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;
 
@@ -123,6 +124,14 @@ 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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