sha1_file: fix error message for alternate objects
When we fail to open a corrupt loose object, we report an error and mention the filename via sha1_file_name(). However, that function will always give us a path in the local repository, whereas the corrupt object may have come from an alternate. The result is a very misleading error message. Teach the open_sha1_file() and stat_sha1_file() helpers to pass back the path they found, so that we can report it correctly. Note that the pointers we return go to static storage (e.g., from sha1_file_name()), which is slightly dangerous. However, these helpers are static local helpers, and the names are used for immediately generating error messages. The simplicity is an acceptable tradeoff for the danger. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King committed
Jan 13, 2017 at 12:54 UTC
771e7d578ee93753f5ac0ed346effd0af3d5a4b4
2 files changed
+41
-15
sha1_file.c
+31
-15
@@ -1613,39 +1613,54 @@ int git_open(const char *name)
1613
}
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}
1615
1616
-static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
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+/*
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+ * Find "sha1" as a loose object in the local repository or in an alternate.
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+ * Returns 0 on success, negative on failure.
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+ *
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+ * The "path" out-parameter will give the path of the object we found (if any).
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+ * Note that it may point to static storage and is only valid until another
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+ * call to sha1_file_name(), etc.
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+ */
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+static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
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+ const char **path)
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{
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struct alternate_object_database *alt;
1628
1620
- if (!lstat(sha1_file_name(sha1), st))
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+ *path = sha1_file_name(sha1);
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+ if (!lstat(*path, st))
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return 0;
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prepare_alt_odb();
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errno = ENOENT;
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for (alt = alt_odb_list; alt; alt = alt->next) {
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- const char *path = alt_sha1_path(alt, sha1);
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- if (!lstat(path, st))
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+ *path = alt_sha1_path(alt, sha1);
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+ if (!lstat(*path, st))
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return 0;
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}
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return -1;
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}
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-static int open_sha1_file(const unsigned char *sha1)
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+/*
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+ * Like stat_sha1_file(), but actually open the object and return the
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+ * descriptor. See the caveats on the "path" parameter above.
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+ */
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+static int open_sha1_file(const unsigned char *sha1, const char **path)
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{
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int fd;
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struct alternate_object_database *alt;
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int most_interesting_errno;
1653
1640
- fd = git_open(sha1_file_name(sha1));
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+ *path = sha1_file_name(sha1);
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+ fd = git_open(*path);
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if (fd >= 0)
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return fd;
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most_interesting_errno = errno;
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prepare_alt_odb();
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for (alt = alt_odb_list; alt; alt = alt->next) {
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- const char *path = alt_sha1_path(alt, sha1);
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- fd = git_open(path);
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+ *path = alt_sha1_path(alt, sha1);
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+ fd = git_open(*path);
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if (fd >= 0)
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return fd;
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if (most_interesting_errno == ENOENT)
@@ -1657,10 +1672,11 @@ static int open_sha1_file(const unsigned char *sha1)
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void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
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{
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+ const char *path;
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void *map;
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int fd;
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- fd = open_sha1_file(sha1);
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+ fd = open_sha1_file(sha1, &path);
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map = NULL;
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if (fd >= 0) {
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struct stat st;
@@ -1669,7 +1685,7 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
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*size = xsize_t(st.st_size);
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if (!*size) {
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/* mmap() is forbidden on empty files */
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- error("object file %s is empty", sha1_file_name(sha1));
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+ error("object file %s is empty", path);
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return NULL;
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}
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map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
@@ -2789,8 +2805,9 @@ static int sha1_loose_object_info(const unsigned char *sha1,
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* object even exists.
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*/
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if (!oi->typep && !oi->typename && !oi->sizep) {
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+ const char *path;
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struct stat st;
2793
- if (stat_sha1_file(sha1, &st) < 0)
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+ if (stat_sha1_file(sha1, &st, &path) < 0)
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return -1;
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if (oi->disk_sizep)
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*oi->disk_sizep = st.st_size;
@@ -2986,6 +3003,8 @@ void *read_sha1_file_extended(const unsigned char *sha1,
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{
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void *data;
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const struct packed_git *p;
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+ const char *path;
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+ struct stat st;
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const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
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3010
errno = 0;
@@ -3001,12 +3020,9 @@ void *read_sha1_file_extended(const unsigned char *sha1,
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die("replacement %s not found for %s",
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sha1_to_hex(repl), sha1_to_hex(sha1));
3022
3004
- if (has_loose_object(repl)) {
3005
- const char *path = sha1_file_name(sha1);
3006
-
3023
+ if (!stat_sha1_file(repl, &st, &path))
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die("loose object %s (stored in %s) is corrupt",
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sha1_to_hex(repl), path);
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- }
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if ((p = has_packed_and_bad(repl)) != NULL)
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die("packed object %s (stored in %s) is corrupt",
t/t1450-fsck.sh
+10
@@ -550,4 +550,14 @@ test_expect_success 'fsck --name-objects' '
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)
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'
552
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+test_expect_success 'alternate objects are correctly blamed' '
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+ test_when_finished "rm -rf alt.git .git/objects/info/alternates" &&
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+ git init --bare alt.git &&
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+ echo "../../alt.git/objects" >.git/objects/info/alternates &&
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+ mkdir alt.git/objects/12 &&
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+ >alt.git/objects/12/34567890123456789012345678901234567890 &&
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+ test_must_fail git fsck >out 2>&1 &&
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+ grep alt.git out
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+'
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+
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test_done