diff options
| -rw-r--r-- | refs.c | 106 |
1 files changed, 72 insertions, 34 deletions
@@ -1197,6 +1197,37 @@ static struct ref_entry *get_packed_ref(const char *refname) return find_ref(get_packed_refs(&ref_cache), refname); } +/* + * A loose ref file doesn't exist; check for a packed ref. The + * options are forwarded from resolve_safe_unsafe(). + */ +static const char *handle_missing_loose_ref(const char *refname, + unsigned char *sha1, + int reading, + int *flag) +{ + struct ref_entry *entry; + + /* + * The loose reference file does not exist; check for a packed + * reference. + */ + entry = get_packed_ref(refname); + if (entry) { + hashcpy(sha1, entry->u.value.sha1); + if (flag) + *flag |= REF_ISPACKED; + return refname; + } + /* The reference is not a packed reference, either. */ + if (reading) { + return NULL; + } else { + hashclr(sha1); + return refname; + } +} + const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag) { int depth = MAXDEPTH; @@ -1221,36 +1252,34 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea git_snpath(path, sizeof(path), "%s", refname); + /* + * 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) { - struct ref_entry *entry; - - if (errno != ENOENT) + if (errno == ENOENT) + return handle_missing_loose_ref(refname, sha1, + reading, flag); + else return NULL; - /* - * The loose reference file does not exist; - * check for a packed reference. - */ - entry = get_packed_ref(refname); - if (entry) { - hashcpy(sha1, entry->u.value.sha1); - if (flag) - *flag |= REF_ISPACKED; - return refname; - } - /* The reference is not a packed reference, either. */ - if (reading) { - return NULL; - } else { - hashclr(sha1); - return refname; - } } /* Follow "normalized" - ie "refs/.." symlinks by hand */ if (S_ISLNK(st.st_mode)) { len = readlink(path, buffer, sizeof(buffer)-1); - if (len < 0) - return NULL; + if (len < 0) { + if (errno == ENOENT || errno == EINVAL) + /* inconsistent with lstat; retry */ + goto stat_ref; + else + return NULL; + } buffer[len] = 0; if (!prefixcmp(buffer, "refs/") && !check_refname_format(buffer, 0)) { @@ -1273,8 +1302,13 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea * a ref */ fd = open(path, O_RDONLY); - if (fd < 0) - return NULL; + if (fd < 0) { + if (errno == ENOENT) + /* inconsistent with lstat; retry */ + goto stat_ref; + else + return NULL; + } len = read_in_full(fd, buffer, sizeof(buffer)-1); close(fd); if (len < 0) @@ -1286,8 +1320,19 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea /* * Is it a symbolic ref? */ - if (prefixcmp(buffer, "ref:")) - break; + if (prefixcmp(buffer, "ref:")) { + /* + * Please note that FETCH_HEAD has a second + * line containing other data. + */ + if (get_sha1_hex(buffer, sha1) || + (buffer[40] != '\0' && !isspace(buffer[40]))) { + if (flag) + *flag |= REF_ISBROKEN; + return NULL; + } + return refname; + } if (flag) *flag |= REF_ISSYMREF; buf = buffer + 4; @@ -1300,13 +1345,6 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea } refname = strcpy(refname_buffer, buf); } - /* Please note that FETCH_HEAD has a second line containing other data. */ - if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) { - if (flag) - *flag |= REF_ISBROKEN; - return NULL; - } - return refname; } char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag) |