When putting whole objects in core is unavoidable, try match object
type and size first before actually inflating.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
---
The bypassing has_sha1_object() and doing sha1_object_info() directly mainly to
help avoid unnecessary collision tesst when user run this command on
an in-repo pack. But I realized there's no sure way to check if the
given pack (especiall with --stdin) is in repo. So I'll drop 5/6 and
6/6. People just have to set GIT_DIR=/nowhere.
builtin/index-pack.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++---
t/t5300-pack-object.sh | 5 +++
2 files changed, 82 insertions(+), 5 deletions(-)
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 9129299..8b5c1eb 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -9,6 +9,7 @@
#include "progress.h"
#include "fsck.h"
#include "exec_cmd.h"
+#include "streaming.h"
#include "thread-utils.h"
static const char index_pack_usage[] =
@@ -621,31 +622,102 @@ static void find_delta_children(const union delta_base *base,
*last_index = last;
}
+struct compare_data {
+ struct object_entry *entry;
+ struct git_istream *st;
+ unsigned char *buf;
+ unsigned long buf_size;
+};
+
+static int compare_objects(const unsigned char *buf, unsigned long size,
+ void *cb_data)
+{
+ struct compare_data *data = cb_data;
+
+ if (data->buf_size < size) {
+ free(data->buf);
+ data->buf = xmalloc(size);
+ data->buf_size = size;
+ }
+
+ while (size) {
+ ssize_t len = read_istream(data->st, data->buf, size);
+ if (len == 0)
+ die(_("SHA1 COLLISION FOUND WITH %s !"),
+ sha1_to_hex(data->entry->idx.sha1));
+ if (len < 0)
+ die(_("unable to read %s"),
+ sha1_to_hex(data->entry->idx.sha1));
+ if (memcmp(buf, data->buf, len))
+ die(_("SHA1 COLLISION FOUND WITH %s !"),
+ sha1_to_hex(data->entry->idx.sha1));
+ size -= len;
+ buf += len;
+ }
+ return 0;
+}
+
+static int check_collison(struct object_entry *entry)
+{
+ struct compare_data data;
+ enum object_type type;
+ unsigned long size;
+
+ if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
+ return -1;
+
+ memset(&data, 0, sizeof(data));
+ data.entry = entry;
+ data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
+ if (!data.st)
+ return -1;
+ if (size != entry->size || type != entry->type)
+ die(_("SHA1 COLLISION FOUND WITH %s !"),
+ sha1_to_hex(entry->idx.sha1));
+ unpack_data(entry, compare_objects, &data);
+ close_istream(data.st);
+ free(data.buf);
+ return 0;
+}
+
static void sha1_object(const void *data, struct object_entry *obj_entry,
unsigned long size, enum object_type type,
const unsigned char *sha1)
{
void *new_data = NULL;
+ int collision_test_needed;
assert(data || obj_entry);
read_lock();
- if (has_sha1_file(sha1)) {
+ collision_test_needed = has_sha1_file(sha1);
+ read_unlock();
+
+ if (collision_test_needed && !data) {
+ read_lock();
+ if (!check_collison(obj_entry))
+ collision_test_needed = 0;
+ read_unlock();
+ }
+ if (collision_test_needed) {
void *has_data;
enum object_type has_type;
unsigned long has_size;
- if (!data)
- data = new_data = get_data_from_pack(obj_entry);
+ read_lock();
+ has_type = sha1_object_info(sha1, &has_size);
+ if (has_type != type || has_size != size)
+ die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
has_data = read_sha1_file(sha1, &has_type, &has_size);
read_unlock();
+ if (!data)
+ data = new_data = get_data_from_pack(obj_entry);
if (!has_data)
die(_("cannot read existing object %s"), sha1_to_hex(sha1));
if (size != has_size || type != has_type ||
memcmp(data, has_data, size) != 0)
die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
free(has_data);
- } else
- read_unlock();
+ }
if (strict) {
read_lock();
diff --git a/t/t5300-pack-object.sh b/t/t5300-pack-object.sh
index d9d856b..300ed91 100755
--- a/t/t5300-pack-object.sh
+++ b/t/t5300-pack-object.sh
@@ -418,4 +418,9 @@ test_expect_success \
'test_must_fail git index-pack -o bad.idx test-3.pack 2>msg &&
grep "SHA1 COLLISION FOUND" msg'
+test_expect_success \
+ 'make sure index-pack detects the SHA1 collision (large blobs)' \
+ 'test_must_fail git -c core.bigfilethreshold=1 index-pack -o bad.idx test-3.pack 2>msg &&
+ grep "SHA1 COLLISION FOUND" msg'
+
test_done
--
1.7.10.2.549.g9354186
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