From: Lidong Yan <502024330056@xxxxxxxxxxxxxxxx>
This patch add "load corrupt bitmap" test case in t5310-pack-bitmaps.sh.
This test case intentionally corrupt the "xor_offset" field of the first
entry. To find position of first entry in *.bitmap, we need to skip 4
ewah_bitmaps before entries. And I add a function `skip_ewah_bitmap()`
to do this.
Signed-off-by: Lidong Yan <502024330056@xxxxxxxxxxxxxxxx>
---
t/t5310-pack-bitmaps.sh | 50 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/t/t5310-pack-bitmaps.sh b/t/t5310-pack-bitmaps.sh
index a62b463eaf09..537a507957bb 100755
--- a/t/t5310-pack-bitmaps.sh
+++ b/t/t5310-pack-bitmaps.sh
@@ -26,6 +26,18 @@ has_any () {
grep -Ff "$1" "$2"
}
+skip_ewah_bitmap() {
+ local bitmap="$1" &&
+ local offset="$2" &&
+ local size= &&
+
+ offset=$(($offset + 4)) &&
+ size=0x$(od -An -v -t x1 -j $offset -N 4 $bitmap | tr -d ' \n') &&
+ size=$(($size * 8)) &&
+ offset=$(($offset + 4 + $size + 4)) &&
+ echo $offset
+}
+
# Since name-hash values are stored in the .bitmap files, add a test
# that checks that the name-hash calculations are stable across versions.
# Not exhaustive, but these hashing algorithms would be hard to change
@@ -486,6 +498,44 @@ test_bitmap_cases () {
grep "ignoring extra bitmap" trace2.txt
)
'
+
+ # A `.bitmap` file has the following structure:
+ # | Header | Commits | Trees | Blobs | Tags | Entries... |
+ #
+ # - The header is 32 bytes long when using SHA-1.
+ # - Commits, Trees, Blobs, and Tags are all stored as EWAH bitmaps.
+ #
+ # This test intentionally corrupts the `xor_offset` field of the first entry
+ # to verify robustness against malformed bitmap data.
+ test_expect_success 'load corrupt bitmap' '
+ rm -fr repo &&
+ git init repo &&
+ test_when_finished "rm -fr repo" &&
+ (
+ cd repo &&
+ git config pack.writeBitmapLookupTable '"$writeLookupTable"' &&
+
+ test_commit base &&
+
+ git repack -adb &&
+ bitmap="$(ls .git/objects/pack/pack-*.bitmap)" &&
+ chmod +w "$bitmap" &&
+
+ hdr_sz=$((12 + $(test_oid rawsz))) &&
+ offset=$(skip_ewah_bitmap $bitmap $hdr_sz) &&
+ offset=$(skip_ewah_bitmap $bitmap $offset) &&
+ offset=$(skip_ewah_bitmap $bitmap $offset) &&
+ offset=$(skip_ewah_bitmap $bitmap $offset) &&
+ offset=$((offset + 4)) &&
+
+ printf '\161' |
+ dd of=$bitmap count=1 bs=1 conv=notrunc seek=$offset &&
+
+ git rev-list --count HEAD > expect &&
+ git rev-list --use-bitmap-index --count HEAD > actual &&
+ test_cmp expect actual
+ )
+ '
}
test_bitmap_cases
--
gitgitgadget
