Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
---
cache.h | 11 ++++
refs.c | 204 ++++++++++++++++++++++++++++++++++------------------------------
2 files changed, 120 insertions(+), 95 deletions(-)
diff --git a/cache.h b/cache.h
index 5ffbafb..40a63d9 100644
--- a/cache.h
+++ b/cache.h
@@ -1003,6 +1003,17 @@ extern int read_ref(const char *refname, unsigned char *sha1);
extern const char *resolve_ref_unsafe(const char *ref, unsigned char *sha1, int reading, int *flag);
extern char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag);
extern int resolve_ref(const char *refname, struct strbuf *result, unsigned char *sha1, int reading, int *flag);
+/*
+ * Given a ref in "ref" and its path, returns
+ *
+ * -2 failed to open with ENOENT, the caller is responsible for
+ * checking missing loose ref (see resolve_ref for example)
+ * -1 if there's an error, "ref" can no longer be trusted, "flag" may
+ * be set. errno is valid.
+ * 0 this is a symref, "ref" now contains the linked ref
+ * +1 normal ref, "sha1" is valid
+ */
+extern int parse_ref(const char *path, struct strbuf *ref, unsigned char *sha1, int *flag);
extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
diff --git a/refs.c b/refs.c
index bec2bb1..2769f20 100644
--- a/refs.c
+++ b/refs.c
@@ -1533,6 +1533,105 @@ static int handle_missing_loose_ref(const char *refname,
}
}
+int parse_ref(const char *path, struct strbuf *ref,
+ unsigned char *sha1, int *flag)
+{
+ struct strbuf buffer = STRBUF_INIT;
+ struct stat st;
+ const char *buf;
+
+ /*
+ * We might have to loop back here to avoid a race condition:
+ * first we lstat() the file, then we try to read it as a link
+ * or as a file. But if somebody changes the type of the file
+ * (file <-> directory <-> symlink) between the lstat() and
+ * reading, then we don't want to report that as an error but
+ * rather try again starting with the lstat().
+ */
+stat_ref:
+ if (lstat(path, &st) < 0)
+ return errno == ENOENT ? -2 : -1;
+
+ /* Follow "normalized" - ie "refs/.." symlinks by hand */
+ if (S_ISLNK(st.st_mode)) {
+ struct strbuf new_path = STRBUF_INIT;
+ if (strbuf_readlink(&new_path, path, 256) < 0) {
+ strbuf_release(&new_path);
+ if (errno == ENOENT || errno == EINVAL)
+ /* inconsistent with lstat; retry */
+ goto stat_ref;
+ else
+ return -1;
+ }
+ if (starts_with(new_path.buf, "refs/") &&
+ !check_refname_format(new_path.buf, 0)) {
+ strbuf_reset(ref);
+ strbuf_addbuf(ref, &new_path);
+ if (flag)
+ *flag |= REF_ISSYMREF;
+ strbuf_release(&new_path);
+ return 0;
+ }
+ strbuf_release(&new_path);
+ }
+
+ /* Is it a directory? */
+ if (S_ISDIR(st.st_mode)) {
+ errno = EISDIR;
+ return -1;
+ }
+
+ /*
+ * Anything else, just open it and try to use it as
+ * a ref
+ */
+ if (strbuf_read_file(&buffer, path, 256) < 0) {
+ strbuf_release(&buffer);
+ if (errno == ENOENT)
+ /* inconsistent with lstat; retry */
+ goto stat_ref;
+ else
+ return -1;
+ }
+ strbuf_rtrim(&buffer);
+
+ /*
+ * Is it a symbolic ref?
+ */
+ if (!skip_prefix(buffer.buf, "ref:", &buf)) {
+ int ret;
+ /*
+ * Please note that FETCH_HEAD has a second line
+ * containing other data.
+ */
+ if (get_sha1_hex(buffer.buf, sha1) ||
+ (buffer.buf[40] != '\0' && !isspace(buffer.buf[40]))) {
+ if (flag)
+ *flag |= REF_ISBROKEN;
+ errno = EINVAL;
+ ret = -1;
+ } else
+ ret = 1;
+ strbuf_release(&buffer);
+ return ret;
+ }
+ if (flag)
+ *flag |= REF_ISSYMREF;
+ while (isspace(*buf))
+ buf++;
+ if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
+ if (flag)
+ *flag |= REF_ISBROKEN;
+ strbuf_release(&buffer);
+ errno = EINVAL;
+ return -1;
+ }
+ strbuf_reset(ref);
+ strbuf_addstr(ref, buf);
+ strbuf_release(&buffer);
+ return 0;
+}
+
/*
* 'result' content will be destroyed. Its value may be undefined if
* resolve_ref returns -1.
@@ -1542,9 +1641,8 @@ static int handle_missing_loose_ref(const char *refname,
int resolve_ref(const char *refname, struct strbuf *result,
unsigned char *sha1, int reading, int *flag)
{
- struct strbuf buffer = STRBUF_INIT;
int depth = MAXDEPTH;
- int ret = -1;
+ int ret = 0;
if (flag)
*flag = 0;
@@ -1557,108 +1655,24 @@ int resolve_ref(const char *refname, struct strbuf *result,
strbuf_reset(result);
strbuf_addstr(result, refname);
- for (;;) {
+ while (!ret) {
char path[PATH_MAX];
- const char *ref = result->buf;
- struct stat st;
- const char *buf;
if (--depth < 0) {
errno = ELOOP;
+ ret = -1;
break;
}
- git_snpath(path, sizeof(path), "%s", ref);
-
- /*
- * We might have to loop back here to avoid a race
- * condition: first we lstat() the file, then we try
- * to read it as a link or as a file. But if somebody
- * changes the type of the file (file <-> directory
- * <-> symlink) between the lstat() and reading, then
- * we don't want to report that as an error but rather
- * try again starting with the lstat().
- */
- stat_ref:
- if (lstat(path, &st) < 0) {
- if (errno == ENOENT)
- ret = handle_missing_loose_ref(ref, sha1,
- reading, flag);
- break;
+ git_snpath(path, sizeof(path), "%s", result->buf);
+ ret = parse_ref(path, result, sha1, flag);
+ if (ret == -2) {
+ ret = handle_missing_loose_ref(result->buf, sha1,
+ reading, flag);
+ ret = ret ? -1 : 1;
}
-
- /* Follow "normalized" - ie "refs/.." symlinks by hand */
- if (S_ISLNK(st.st_mode)) {
- /* no need to reset buffer, strbuf_readlink does that */
- if (strbuf_readlink(&buffer, path, 256) < 0) {
- if (errno == ENOENT || errno == EINVAL)
- /* inconsistent with lstat; retry */
- goto stat_ref;
- else
- break;
- }
- if (starts_with(buffer.buf, "refs/") &&
- !check_refname_format(buffer.buf, 0)) {
- strbuf_reset(result);
- strbuf_addbuf(result, &buffer);
- if (flag)
- *flag |= REF_ISSYMREF;
- continue;
- }
- }
-
- /* Is it a directory? */
- if (S_ISDIR(st.st_mode)) {
- errno = EISDIR;
- break;
- }
-
- /*
- * Anything else, just open it and try to use it as
- * a ref
- */
- strbuf_reset(&buffer);
- if (strbuf_read_file(&buffer, path, 256) < 0) {
- if (errno == ENOENT)
- /* inconsistent with lstat; retry */
- goto stat_ref;
- else
- break;
- }
- strbuf_rtrim(&buffer);
-
- /*
- * Is it a symbolic ref?
- */
- if (!skip_prefix(buffer.buf, "ref:", &buf)) {
- /*
- * Please note that FETCH_HEAD has a second
- * line containing other data.
- */
- if (get_sha1_hex(buffer.buf, sha1) ||
- (buffer.buf[40] != '\0' && !isspace(buffer.buf[40]))) {
- if (flag)
- *flag |= REF_ISBROKEN;
- errno = EINVAL;
- } else
- ret = 0;
- break;
- }
- if (flag)
- *flag |= REF_ISSYMREF;
- while (isspace(*buf))
- buf++;
- if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
- if (flag)
- *flag |= REF_ISBROKEN;
- errno = EINVAL;
- break;
- }
- strbuf_reset(result);
- strbuf_addstr(result, buf);
}
- strbuf_release(&buffer);
- return ret;
+ return ret > 0 ? 0 : -1;
}
const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
--
1.9.1.346.ga2b5940
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