[PATCH v2 06/11] multi-pack-index: verify oid fanout order

[Derrick Stolee via GitGitGadget]

From: Derrick Stolee <dsto...@microsoft.com>

Signed-off-by: Derrick Stolee <dsto...@microsoft.com>
---
 midx.c                      | 9 +++++++++
 t/t5319-multi-pack-index.sh | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/midx.c b/midx.c
index a02b19efc1..dfd26b4d74 100644
--- a/midx.c
+++ b/midx.c
@@ -950,5 +950,14 @@ int verify_midx_file(const char *object_dir)
                        midx_report("failed to load pack in position %d", i);
        }
 
+       for (i = 0; i < 255; i++) {
+               uint32_t oid_fanout1 = ntohl(m->chunk_oid_fanout[i]);
+               uint32_t oid_fanout2 = ntohl(m->chunk_oid_fanout[i + 1]);
+
+               if (oid_fanout1 > oid_fanout2)
+                       midx_report(_("oid fanout out of order: fanout[%d] = 
%"PRIx32" > %"PRIx32" = fanout[%d]"),
+                                   i, oid_fanout1, oid_fanout2, i + 1);
+       }
+
        return verify_midx_error;
 }
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 0a566afb05..47a54e138d 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -186,6 +186,9 @@ MIDX_CHUNK_LOOKUP_WIDTH=12
 MIDX_OFFSET_PACKNAMES=$(($MIDX_HEADER_SIZE + \
                         $MIDX_NUM_CHUNKS * $MIDX_CHUNK_LOOKUP_WIDTH))
 MIDX_BYTE_PACKNAME_ORDER=$(($MIDX_OFFSET_PACKNAMES + 2))
+MIDX_OFFSET_OID_FANOUT=$(($MIDX_OFFSET_PACKNAMES + 652))
+MIDX_OID_FANOUT_WIDTH=4
+MIDX_BYTE_OID_FANOUT_ORDER=$((MIDX_OFFSET_OID_FANOUT + 250 * 
$MIDX_OID_FANOUT_WIDTH + 1))
 
 test_expect_success 'verify bad version' '
        corrupt_midx_and_verify $MIDX_BYTE_VERSION "\00" $objdir \
@@ -227,6 +230,11 @@ test_expect_success 'verify packnames out of order' '
                "failed to load pack"
 '
 
+test_expect_success 'verify oid fanout out of order' '
+       corrupt_midx_and_verify $MIDX_BYTE_OID_FANOUT_ORDER "\01" $objdir \
+               "oid fanout out of order"
+'
+
 test_expect_success 'repack removes multi-pack-index' '
        test_path_is_file $objdir/pack/multi-pack-index &&
        git repack -adf &&
-- 
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