git/refs.c
Junio C Hamano 970957dbad Merge branch 'jc/maint-refs-dangling' into maint
* jc/maint-refs-dangling:
  refs: ref entry with NULL sha1 is can be a dangling symref
2010-03-31 15:09:32 -07:00

1836 lines
44 KiB
C

#include "cache.h"
#include "refs.h"
#include "object.h"
#include "tag.h"
#include "dir.h"
/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
#define REF_KNOWS_PEELED 04
#define REF_BROKEN 010
struct ref_list {
struct ref_list *next;
unsigned char flag; /* ISSYMREF? ISPACKED? */
unsigned char sha1[20];
unsigned char peeled[20];
char name[FLEX_ARRAY];
};
static const char *parse_ref_line(char *line, unsigned char *sha1)
{
/*
* 42: the answer to everything.
*
* In this case, it happens to be the answer to
* 40 (length of sha1 hex representation)
* +1 (space in between hex and name)
* +1 (newline at the end of the line)
*/
int len = strlen(line) - 42;
if (len <= 0)
return NULL;
if (get_sha1_hex(line, sha1) < 0)
return NULL;
if (!isspace(line[40]))
return NULL;
line += 41;
if (isspace(*line))
return NULL;
if (line[len] != '\n')
return NULL;
line[len] = 0;
return line;
}
static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
int flag, struct ref_list *list,
struct ref_list **new_entry)
{
int len;
struct ref_list *entry;
/* Allocate it and add it in.. */
len = strlen(name) + 1;
entry = xmalloc(sizeof(struct ref_list) + len);
hashcpy(entry->sha1, sha1);
hashclr(entry->peeled);
memcpy(entry->name, name, len);
entry->flag = flag;
entry->next = list;
if (new_entry)
*new_entry = entry;
return entry;
}
/* merge sort the ref list */
static struct ref_list *sort_ref_list(struct ref_list *list)
{
int psize, qsize, last_merge_count, cmp;
struct ref_list *p, *q, *l, *e;
struct ref_list *new_list = list;
int k = 1;
int merge_count = 0;
if (!list)
return list;
do {
last_merge_count = merge_count;
merge_count = 0;
psize = 0;
p = new_list;
q = new_list;
new_list = NULL;
l = NULL;
while (p) {
merge_count++;
while (psize < k && q->next) {
q = q->next;
psize++;
}
qsize = k;
while ((psize > 0) || (qsize > 0 && q)) {
if (qsize == 0 || !q) {
e = p;
p = p->next;
psize--;
} else if (psize == 0) {
e = q;
q = q->next;
qsize--;
} else {
cmp = strcmp(q->name, p->name);
if (cmp < 0) {
e = q;
q = q->next;
qsize--;
} else if (cmp > 0) {
e = p;
p = p->next;
psize--;
} else {
if (hashcmp(q->sha1, p->sha1))
die("Duplicated ref, and SHA1s don't match: %s",
q->name);
warning("Duplicated ref: %s", q->name);
e = q;
q = q->next;
qsize--;
free(e);
e = p;
p = p->next;
psize--;
}
}
e->next = NULL;
if (l)
l->next = e;
if (!new_list)
new_list = e;
l = e;
}
p = q;
};
k = k * 2;
} while ((last_merge_count != merge_count) || (last_merge_count != 1));
return new_list;
}
/*
* Future: need to be in "struct repository"
* when doing a full libification.
*/
static struct cached_refs {
char did_loose;
char did_packed;
struct ref_list *loose;
struct ref_list *packed;
} cached_refs;
static struct ref_list *current_ref;
static struct ref_list *extra_refs;
static void free_ref_list(struct ref_list *list)
{
struct ref_list *next;
for ( ; list; list = next) {
next = list->next;
free(list);
}
}
static void invalidate_cached_refs(void)
{
struct cached_refs *ca = &cached_refs;
if (ca->did_loose && ca->loose)
free_ref_list(ca->loose);
if (ca->did_packed && ca->packed)
free_ref_list(ca->packed);
ca->loose = ca->packed = NULL;
ca->did_loose = ca->did_packed = 0;
}
static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
{
struct ref_list *list = NULL;
struct ref_list *last = NULL;
char refline[PATH_MAX];
int flag = REF_ISPACKED;
while (fgets(refline, sizeof(refline), f)) {
unsigned char sha1[20];
const char *name;
static const char header[] = "# pack-refs with:";
if (!strncmp(refline, header, sizeof(header)-1)) {
const char *traits = refline + sizeof(header) - 1;
if (strstr(traits, " peeled "))
flag |= REF_KNOWS_PEELED;
/* perhaps other traits later as well */
continue;
}
name = parse_ref_line(refline, sha1);
if (name) {
list = add_ref(name, sha1, flag, list, &last);
continue;
}
if (last &&
refline[0] == '^' &&
strlen(refline) == 42 &&
refline[41] == '\n' &&
!get_sha1_hex(refline + 1, sha1))
hashcpy(last->peeled, sha1);
}
cached_refs->packed = sort_ref_list(list);
}
void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
{
extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
}
void clear_extra_refs(void)
{
free_ref_list(extra_refs);
extra_refs = NULL;
}
static struct ref_list *get_packed_refs(void)
{
if (!cached_refs.did_packed) {
FILE *f = fopen(git_path("packed-refs"), "r");
cached_refs.packed = NULL;
if (f) {
read_packed_refs(f, &cached_refs);
fclose(f);
}
cached_refs.did_packed = 1;
}
return cached_refs.packed;
}
static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
{
DIR *dir = opendir(git_path("%s", base));
if (dir) {
struct dirent *de;
int baselen = strlen(base);
char *ref = xmalloc(baselen + 257);
memcpy(ref, base, baselen);
if (baselen && base[baselen-1] != '/')
ref[baselen++] = '/';
while ((de = readdir(dir)) != NULL) {
unsigned char sha1[20];
struct stat st;
int flag;
int namelen;
if (de->d_name[0] == '.')
continue;
namelen = strlen(de->d_name);
if (namelen > 255)
continue;
if (has_extension(de->d_name, ".lock"))
continue;
memcpy(ref + baselen, de->d_name, namelen+1);
if (stat(git_path("%s", ref), &st) < 0)
continue;
if (S_ISDIR(st.st_mode)) {
list = get_ref_dir(ref, list);
continue;
}
if (!resolve_ref(ref, sha1, 1, &flag)) {
hashclr(sha1);
flag |= REF_BROKEN;
}
list = add_ref(ref, sha1, flag, list, NULL);
}
free(ref);
closedir(dir);
}
return sort_ref_list(list);
}
struct warn_if_dangling_data {
FILE *fp;
const char *refname;
const char *msg_fmt;
};
static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
int flags, void *cb_data)
{
struct warn_if_dangling_data *d = cb_data;
const char *resolves_to;
unsigned char junk[20];
if (!(flags & REF_ISSYMREF))
return 0;
resolves_to = resolve_ref(refname, junk, 0, NULL);
if (!resolves_to || strcmp(resolves_to, d->refname))
return 0;
fprintf(d->fp, d->msg_fmt, refname);
return 0;
}
void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
{
struct warn_if_dangling_data data = { fp, refname, msg_fmt };
for_each_rawref(warn_if_dangling_symref, &data);
}
static struct ref_list *get_loose_refs(void)
{
if (!cached_refs.did_loose) {
cached_refs.loose = get_ref_dir("refs", NULL);
cached_refs.did_loose = 1;
}
return cached_refs.loose;
}
/* We allow "recursive" symbolic refs. Only within reason, though */
#define MAXDEPTH 5
#define MAXREFLEN (1024)
static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
{
FILE *f;
struct cached_refs refs;
struct ref_list *ref;
int retval;
strcpy(name + pathlen, "packed-refs");
f = fopen(name, "r");
if (!f)
return -1;
read_packed_refs(f, &refs);
fclose(f);
ref = refs.packed;
retval = -1;
while (ref) {
if (!strcmp(ref->name, refname)) {
retval = 0;
memcpy(result, ref->sha1, 20);
break;
}
ref = ref->next;
}
free_ref_list(refs.packed);
return retval;
}
static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
{
int fd, len = strlen(refname);
char buffer[128], *p;
if (recursion > MAXDEPTH || len > MAXREFLEN)
return -1;
memcpy(name + pathlen, refname, len+1);
fd = open(name, O_RDONLY);
if (fd < 0)
return resolve_gitlink_packed_ref(name, pathlen, refname, result);
len = read(fd, buffer, sizeof(buffer)-1);
close(fd);
if (len < 0)
return -1;
while (len && isspace(buffer[len-1]))
len--;
buffer[len] = 0;
/* Was it a detached head or an old-fashioned symlink? */
if (!get_sha1_hex(buffer, result))
return 0;
/* Symref? */
if (strncmp(buffer, "ref:", 4))
return -1;
p = buffer + 4;
while (isspace(*p))
p++;
return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
}
int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
{
int len = strlen(path), retval;
char *gitdir;
const char *tmp;
while (len && path[len-1] == '/')
len--;
if (!len)
return -1;
gitdir = xmalloc(len + MAXREFLEN + 8);
memcpy(gitdir, path, len);
memcpy(gitdir + len, "/.git", 6);
len += 5;
tmp = read_gitfile_gently(gitdir);
if (tmp) {
free(gitdir);
len = strlen(tmp);
gitdir = xmalloc(len + MAXREFLEN + 3);
memcpy(gitdir, tmp, len);
}
gitdir[len] = '/';
gitdir[++len] = '\0';
retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
free(gitdir);
return retval;
}
/*
* If the "reading" argument is set, this function finds out what _object_
* the ref points at by "reading" the ref. The ref, if it is not symbolic,
* has to exist, and if it is symbolic, it has to point at an existing ref,
* because the "read" goes through the symref to the ref it points at.
*
* The access that is not "reading" may often be "writing", but does not
* have to; it can be merely checking _where it leads to_. If it is a
* prelude to "writing" to the ref, a write to a symref that points at
* yet-to-be-born ref will create the real ref pointed by the symref.
* reading=0 allows the caller to check where such a symref leads to.
*/
const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
{
int depth = MAXDEPTH;
ssize_t len;
char buffer[256];
static char ref_buffer[256];
if (flag)
*flag = 0;
for (;;) {
char path[PATH_MAX];
struct stat st;
char *buf;
int fd;
if (--depth < 0)
return NULL;
git_snpath(path, sizeof(path), "%s", ref);
/* Special case: non-existing file. */
if (lstat(path, &st) < 0) {
struct ref_list *list = get_packed_refs();
while (list) {
if (!strcmp(ref, list->name)) {
hashcpy(sha1, list->sha1);
if (flag)
*flag |= REF_ISPACKED;
return ref;
}
list = list->next;
}
if (reading || errno != ENOENT)
return NULL;
hashclr(sha1);
return ref;
}
/* Follow "normalized" - ie "refs/.." symlinks by hand */
if (S_ISLNK(st.st_mode)) {
len = readlink(path, buffer, sizeof(buffer)-1);
if (len >= 5 && !memcmp("refs/", buffer, 5)) {
buffer[len] = 0;
strcpy(ref_buffer, buffer);
ref = ref_buffer;
if (flag)
*flag |= REF_ISSYMREF;
continue;
}
}
/* Is it a directory? */
if (S_ISDIR(st.st_mode)) {
errno = EISDIR;
return NULL;
}
/*
* Anything else, just open it and try to use it as
* a ref
*/
fd = open(path, O_RDONLY);
if (fd < 0)
return NULL;
len = read_in_full(fd, buffer, sizeof(buffer)-1);
close(fd);
/*
* Is it a symbolic ref?
*/
if (len < 4 || memcmp("ref:", buffer, 4))
break;
buf = buffer + 4;
len -= 4;
while (len && isspace(*buf))
buf++, len--;
while (len && isspace(buf[len-1]))
len--;
buf[len] = 0;
memcpy(ref_buffer, buf, len + 1);
ref = ref_buffer;
if (flag)
*flag |= REF_ISSYMREF;
}
if (len < 40 || get_sha1_hex(buffer, sha1))
return NULL;
return ref;
}
/* The argument to filter_refs */
struct ref_filter {
const char *pattern;
each_ref_fn *fn;
void *cb_data;
};
int read_ref(const char *ref, unsigned char *sha1)
{
if (resolve_ref(ref, sha1, 1, NULL))
return 0;
return -1;
}
#define DO_FOR_EACH_INCLUDE_BROKEN 01
static int do_one_ref(const char *base, each_ref_fn fn, int trim,
int flags, void *cb_data, struct ref_list *entry)
{
if (strncmp(base, entry->name, trim))
return 0;
if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
if (entry->flag & REF_BROKEN)
return 0; /* ignore dangling symref */
if (!has_sha1_file(entry->sha1)) {
error("%s does not point to a valid object!", entry->name);
return 0;
}
}
current_ref = entry;
return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
}
static int filter_refs(const char *ref, const unsigned char *sha, int flags,
void *data)
{
struct ref_filter *filter = (struct ref_filter *)data;
if (fnmatch(filter->pattern, ref, 0))
return 0;
return filter->fn(ref, sha, flags, filter->cb_data);
}
int peel_ref(const char *ref, unsigned char *sha1)
{
int flag;
unsigned char base[20];
struct object *o;
if (current_ref && (current_ref->name == ref
|| !strcmp(current_ref->name, ref))) {
if (current_ref->flag & REF_KNOWS_PEELED) {
hashcpy(sha1, current_ref->peeled);
return 0;
}
hashcpy(base, current_ref->sha1);
goto fallback;
}
if (!resolve_ref(ref, base, 1, &flag))
return -1;
if ((flag & REF_ISPACKED)) {
struct ref_list *list = get_packed_refs();
while (list) {
if (!strcmp(list->name, ref)) {
if (list->flag & REF_KNOWS_PEELED) {
hashcpy(sha1, list->peeled);
return 0;
}
/* older pack-refs did not leave peeled ones */
break;
}
list = list->next;
}
}
fallback:
o = parse_object(base);
if (o && o->type == OBJ_TAG) {
o = deref_tag(o, ref, 0);
if (o) {
hashcpy(sha1, o->sha1);
return 0;
}
}
return -1;
}
static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
int flags, void *cb_data)
{
int retval = 0;
struct ref_list *packed = get_packed_refs();
struct ref_list *loose = get_loose_refs();
struct ref_list *extra;
for (extra = extra_refs; extra; extra = extra->next)
retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
while (packed && loose) {
struct ref_list *entry;
int cmp = strcmp(packed->name, loose->name);
if (!cmp) {
packed = packed->next;
continue;
}
if (cmp > 0) {
entry = loose;
loose = loose->next;
} else {
entry = packed;
packed = packed->next;
}
retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
if (retval)
goto end_each;
}
for (packed = packed ? packed : loose; packed; packed = packed->next) {
retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
if (retval)
goto end_each;
}
end_each:
current_ref = NULL;
return retval;
}
int head_ref(each_ref_fn fn, void *cb_data)
{
unsigned char sha1[20];
int flag;
if (resolve_ref("HEAD", sha1, 1, &flag))
return fn("HEAD", sha1, flag, cb_data);
return 0;
}
int for_each_ref(each_ref_fn fn, void *cb_data)
{
return do_for_each_ref("refs/", fn, 0, 0, cb_data);
}
int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
{
return do_for_each_ref(prefix, fn, strlen(prefix), 0, cb_data);
}
int for_each_tag_ref(each_ref_fn fn, void *cb_data)
{
return for_each_ref_in("refs/tags/", fn, cb_data);
}
int for_each_branch_ref(each_ref_fn fn, void *cb_data)
{
return for_each_ref_in("refs/heads/", fn, cb_data);
}
int for_each_remote_ref(each_ref_fn fn, void *cb_data)
{
return for_each_ref_in("refs/remotes/", fn, cb_data);
}
int for_each_replace_ref(each_ref_fn fn, void *cb_data)
{
return do_for_each_ref("refs/replace/", fn, 13, 0, cb_data);
}
int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
const char *prefix, void *cb_data)
{
struct strbuf real_pattern = STRBUF_INIT;
struct ref_filter filter;
int ret;
if (!prefix && prefixcmp(pattern, "refs/"))
strbuf_addstr(&real_pattern, "refs/");
else if (prefix)
strbuf_addstr(&real_pattern, prefix);
strbuf_addstr(&real_pattern, pattern);
if (!has_glob_specials(pattern)) {
/* Append implied '/' '*' if not present. */
if (real_pattern.buf[real_pattern.len - 1] != '/')
strbuf_addch(&real_pattern, '/');
/* No need to check for '*', there is none. */
strbuf_addch(&real_pattern, '*');
}
filter.pattern = real_pattern.buf;
filter.fn = fn;
filter.cb_data = cb_data;
ret = for_each_ref(filter_refs, &filter);
strbuf_release(&real_pattern);
return ret;
}
int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
{
return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
}
int for_each_rawref(each_ref_fn fn, void *cb_data)
{
return do_for_each_ref("refs/", fn, 0,
DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
}
/*
* Make sure "ref" is something reasonable to have under ".git/refs/";
* We do not like it if:
*
* - any path component of it begins with ".", or
* - it has double dots "..", or
* - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
* - it ends with a "/".
* - it ends with ".lock"
* - it contains a "\" (backslash)
*/
static inline int bad_ref_char(int ch)
{
if (((unsigned) ch) <= ' ' ||
ch == '~' || ch == '^' || ch == ':' || ch == '\\')
return 1;
/* 2.13 Pattern Matching Notation */
if (ch == '?' || ch == '[') /* Unsupported */
return 1;
if (ch == '*') /* Supported at the end */
return 2;
return 0;
}
int check_ref_format(const char *ref)
{
int ch, level, bad_type, last;
int ret = CHECK_REF_FORMAT_OK;
const char *cp = ref;
level = 0;
while (1) {
while ((ch = *cp++) == '/')
; /* tolerate duplicated slashes */
if (!ch)
/* should not end with slashes */
return CHECK_REF_FORMAT_ERROR;
/* we are at the beginning of the path component */
if (ch == '.')
return CHECK_REF_FORMAT_ERROR;
bad_type = bad_ref_char(ch);
if (bad_type) {
if (bad_type == 2 && (!*cp || *cp == '/') &&
ret == CHECK_REF_FORMAT_OK)
ret = CHECK_REF_FORMAT_WILDCARD;
else
return CHECK_REF_FORMAT_ERROR;
}
last = ch;
/* scan the rest of the path component */
while ((ch = *cp++) != 0) {
bad_type = bad_ref_char(ch);
if (bad_type)
return CHECK_REF_FORMAT_ERROR;
if (ch == '/')
break;
if (last == '.' && ch == '.')
return CHECK_REF_FORMAT_ERROR;
if (last == '@' && ch == '{')
return CHECK_REF_FORMAT_ERROR;
last = ch;
}
level++;
if (!ch) {
if (ref <= cp - 2 && cp[-2] == '.')
return CHECK_REF_FORMAT_ERROR;
if (level < 2)
return CHECK_REF_FORMAT_ONELEVEL;
if (has_extension(ref, ".lock"))
return CHECK_REF_FORMAT_ERROR;
return ret;
}
}
}
const char *prettify_refname(const char *name)
{
return name + (
!prefixcmp(name, "refs/heads/") ? 11 :
!prefixcmp(name, "refs/tags/") ? 10 :
!prefixcmp(name, "refs/remotes/") ? 13 :
0);
}
const char *ref_rev_parse_rules[] = {
"%.*s",
"refs/%.*s",
"refs/tags/%.*s",
"refs/heads/%.*s",
"refs/remotes/%.*s",
"refs/remotes/%.*s/HEAD",
NULL
};
const char *ref_fetch_rules[] = {
"%.*s",
"refs/%.*s",
"refs/heads/%.*s",
NULL
};
int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
{
const char **p;
const int abbrev_name_len = strlen(abbrev_name);
for (p = rules; *p; p++) {
if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
return 1;
}
}
return 0;
}
static struct ref_lock *verify_lock(struct ref_lock *lock,
const unsigned char *old_sha1, int mustexist)
{
if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
error("Can't verify ref %s", lock->ref_name);
unlock_ref(lock);
return NULL;
}
if (hashcmp(lock->old_sha1, old_sha1)) {
error("Ref %s is at %s but expected %s", lock->ref_name,
sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
unlock_ref(lock);
return NULL;
}
return lock;
}
static int remove_empty_directories(const char *file)
{
/* we want to create a file but there is a directory there;
* if that is an empty directory (or a directory that contains
* only empty directories), remove them.
*/
struct strbuf path;
int result;
strbuf_init(&path, 20);
strbuf_addstr(&path, file);
result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
strbuf_release(&path);
return result;
}
static int is_refname_available(const char *ref, const char *oldref,
struct ref_list *list, int quiet)
{
int namlen = strlen(ref); /* e.g. 'foo/bar' */
while (list) {
/* list->name could be 'foo' or 'foo/bar/baz' */
if (!oldref || strcmp(oldref, list->name)) {
int len = strlen(list->name);
int cmplen = (namlen < len) ? namlen : len;
const char *lead = (namlen < len) ? list->name : ref;
if (!strncmp(ref, list->name, cmplen) &&
lead[cmplen] == '/') {
if (!quiet)
error("'%s' exists; cannot create '%s'",
list->name, ref);
return 0;
}
}
list = list->next;
}
return 1;
}
static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
{
char *ref_file;
const char *orig_ref = ref;
struct ref_lock *lock;
int last_errno = 0;
int type, lflags;
int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
int missing = 0;
lock = xcalloc(1, sizeof(struct ref_lock));
lock->lock_fd = -1;
ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
if (!ref && errno == EISDIR) {
/* we are trying to lock foo but we used to
* have foo/bar which now does not exist;
* it is normal for the empty directory 'foo'
* to remain.
*/
ref_file = git_path("%s", orig_ref);
if (remove_empty_directories(ref_file)) {
last_errno = errno;
error("there are still refs under '%s'", orig_ref);
goto error_return;
}
ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
}
if (type_p)
*type_p = type;
if (!ref) {
last_errno = errno;
error("unable to resolve reference %s: %s",
orig_ref, strerror(errno));
goto error_return;
}
missing = is_null_sha1(lock->old_sha1);
/* When the ref did not exist and we are creating it,
* make sure there is no existing ref that is packed
* whose name begins with our refname, nor a ref whose
* name is a proper prefix of our refname.
*/
if (missing &&
!is_refname_available(ref, NULL, get_packed_refs(), 0)) {
last_errno = ENOTDIR;
goto error_return;
}
lock->lk = xcalloc(1, sizeof(struct lock_file));
lflags = LOCK_DIE_ON_ERROR;
if (flags & REF_NODEREF) {
ref = orig_ref;
lflags |= LOCK_NODEREF;
}
lock->ref_name = xstrdup(ref);
lock->orig_ref_name = xstrdup(orig_ref);
ref_file = git_path("%s", ref);
if (missing)
lock->force_write = 1;
if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
lock->force_write = 1;
if (safe_create_leading_directories(ref_file)) {
last_errno = errno;
error("unable to create directory for %s", ref_file);
goto error_return;
}
lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
error_return:
unlock_ref(lock);
errno = last_errno;
return NULL;
}
struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
{
char refpath[PATH_MAX];
if (check_ref_format(ref))
return NULL;
strcpy(refpath, mkpath("refs/%s", ref));
return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
}
struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
{
switch (check_ref_format(ref)) {
default:
return NULL;
case 0:
case CHECK_REF_FORMAT_ONELEVEL:
return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
}
}
static struct lock_file packlock;
static int repack_without_ref(const char *refname)
{
struct ref_list *list, *packed_ref_list;
int fd;
int found = 0;
packed_ref_list = get_packed_refs();
for (list = packed_ref_list; list; list = list->next) {
if (!strcmp(refname, list->name)) {
found = 1;
break;
}
}
if (!found)
return 0;
fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
if (fd < 0) {
unable_to_lock_error(git_path("packed-refs"), errno);
return error("cannot delete '%s' from packed refs", refname);
}
for (list = packed_ref_list; list; list = list->next) {
char line[PATH_MAX + 100];
int len;
if (!strcmp(refname, list->name))
continue;
len = snprintf(line, sizeof(line), "%s %s\n",
sha1_to_hex(list->sha1), list->name);
/* this should not happen but just being defensive */
if (len > sizeof(line))
die("too long a refname '%s'", list->name);
write_or_die(fd, line, len);
}
return commit_lock_file(&packlock);
}
int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
{
struct ref_lock *lock;
int err, i = 0, ret = 0, flag = 0;
lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
if (!lock)
return 1;
if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
/* loose */
const char *path;
if (!(delopt & REF_NODEREF)) {
i = strlen(lock->lk->filename) - 5; /* .lock */
lock->lk->filename[i] = 0;
path = lock->lk->filename;
} else {
path = git_path("%s", refname);
}
err = unlink_or_warn(path);
if (err && errno != ENOENT)
ret = 1;
if (!(delopt & REF_NODEREF))
lock->lk->filename[i] = '.';
}
/* removing the loose one could have resurrected an earlier
* packed one. Also, if it was not loose we need to repack
* without it.
*/
ret |= repack_without_ref(refname);
unlink_or_warn(git_path("logs/%s", lock->ref_name));
invalidate_cached_refs();
unlock_ref(lock);
return ret;
}
int rename_ref(const char *oldref, const char *newref, const char *logmsg)
{
static const char renamed_ref[] = "RENAMED-REF";
unsigned char sha1[20], orig_sha1[20];
int flag = 0, logmoved = 0;
struct ref_lock *lock;
struct stat loginfo;
int log = !lstat(git_path("logs/%s", oldref), &loginfo);
const char *symref = NULL;
if (log && S_ISLNK(loginfo.st_mode))
return error("reflog for %s is a symlink", oldref);
symref = resolve_ref(oldref, orig_sha1, 1, &flag);
if (flag & REF_ISSYMREF)
return error("refname %s is a symbolic ref, renaming it is not supported",
oldref);
if (!symref)
return error("refname %s not found", oldref);
if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
return 1;
if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
return 1;
lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
if (!lock)
return error("unable to lock %s", renamed_ref);
lock->force_write = 1;
if (write_ref_sha1(lock, orig_sha1, logmsg))
return error("unable to save current sha1 in %s", renamed_ref);
if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
oldref, strerror(errno));
if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
error("unable to delete old %s", oldref);
goto rollback;
}
if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
if (errno==EISDIR) {
if (remove_empty_directories(git_path("%s", newref))) {
error("Directory not empty: %s", newref);
goto rollback;
}
} else {
error("unable to delete existing %s", newref);
goto rollback;
}
}
if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
error("unable to create directory for %s", newref);
goto rollback;
}
retry:
if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
if (errno==EISDIR || errno==ENOTDIR) {
/*
* rename(a, b) when b is an existing
* directory ought to result in ISDIR, but
* Solaris 5.8 gives ENOTDIR. Sheesh.
*/
if (remove_empty_directories(git_path("logs/%s", newref))) {
error("Directory not empty: logs/%s", newref);
goto rollback;
}
goto retry;
} else {
error("unable to move logfile tmp-renamed-log to logs/%s: %s",
newref, strerror(errno));
goto rollback;
}
}
logmoved = log;
lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
if (!lock) {
error("unable to lock %s for update", newref);
goto rollback;
}
lock->force_write = 1;
hashcpy(lock->old_sha1, orig_sha1);
if (write_ref_sha1(lock, orig_sha1, logmsg)) {
error("unable to write current sha1 into %s", newref);
goto rollback;
}
return 0;
rollback:
lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
if (!lock) {
error("unable to lock %s for rollback", oldref);
goto rollbacklog;
}
lock->force_write = 1;
flag = log_all_ref_updates;
log_all_ref_updates = 0;
if (write_ref_sha1(lock, orig_sha1, NULL))
error("unable to write current sha1 into %s", oldref);
log_all_ref_updates = flag;
rollbacklog:
if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
error("unable to restore logfile %s from %s: %s",
oldref, newref, strerror(errno));
if (!logmoved && log &&
rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
error("unable to restore logfile %s from tmp-renamed-log: %s",
oldref, strerror(errno));
return 1;
}
int close_ref(struct ref_lock *lock)
{
if (close_lock_file(lock->lk))
return -1;
lock->lock_fd = -1;
return 0;
}
int commit_ref(struct ref_lock *lock)
{
if (commit_lock_file(lock->lk))
return -1;
lock->lock_fd = -1;
return 0;
}
void unlock_ref(struct ref_lock *lock)
{
/* Do not free lock->lk -- atexit() still looks at them */
if (lock->lk)
rollback_lock_file(lock->lk);
free(lock->ref_name);
free(lock->orig_ref_name);
free(lock);
}
/*
* copy the reflog message msg to buf, which has been allocated sufficiently
* large, while cleaning up the whitespaces. Especially, convert LF to space,
* because reflog file is one line per entry.
*/
static int copy_msg(char *buf, const char *msg)
{
char *cp = buf;
char c;
int wasspace = 1;
*cp++ = '\t';
while ((c = *msg++)) {
if (wasspace && isspace(c))
continue;
wasspace = isspace(c);
if (wasspace)
c = ' ';
*cp++ = c;
}
while (buf < cp && isspace(cp[-1]))
cp--;
*cp++ = '\n';
return cp - buf;
}
static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
const unsigned char *new_sha1, const char *msg)
{
int logfd, written, oflags = O_APPEND | O_WRONLY;
unsigned maxlen, len;
int msglen;
char log_file[PATH_MAX];
char *logrec;
const char *committer;
if (log_all_ref_updates < 0)
log_all_ref_updates = !is_bare_repository();
git_snpath(log_file, sizeof(log_file), "logs/%s", ref_name);
if (log_all_ref_updates &&
(!prefixcmp(ref_name, "refs/heads/") ||
!prefixcmp(ref_name, "refs/remotes/") ||
!prefixcmp(ref_name, "refs/notes/") ||
!strcmp(ref_name, "HEAD"))) {
if (safe_create_leading_directories(log_file) < 0)
return error("unable to create directory for %s",
log_file);
oflags |= O_CREAT;
}
logfd = open(log_file, oflags, 0666);
if (logfd < 0) {
if (!(oflags & O_CREAT) && errno == ENOENT)
return 0;
if ((oflags & O_CREAT) && errno == EISDIR) {
if (remove_empty_directories(log_file)) {
return error("There are still logs under '%s'",
log_file);
}
logfd = open(log_file, oflags, 0666);
}
if (logfd < 0)
return error("Unable to append to %s: %s",
log_file, strerror(errno));
}
adjust_shared_perm(log_file);
msglen = msg ? strlen(msg) : 0;
committer = git_committer_info(0);
maxlen = strlen(committer) + msglen + 100;
logrec = xmalloc(maxlen);
len = sprintf(logrec, "%s %s %s\n",
sha1_to_hex(old_sha1),
sha1_to_hex(new_sha1),
committer);
if (msglen)
len += copy_msg(logrec + len - 1, msg) - 1;
written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
free(logrec);
if (close(logfd) != 0 || written != len)
return error("Unable to append to %s", log_file);
return 0;
}
static int is_branch(const char *refname)
{
return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
}
int write_ref_sha1(struct ref_lock *lock,
const unsigned char *sha1, const char *logmsg)
{
static char term = '\n';
struct object *o;
if (!lock)
return -1;
if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
unlock_ref(lock);
return 0;
}
o = parse_object(sha1);
if (!o) {
error("Trying to write ref %s with nonexistant object %s",
lock->ref_name, sha1_to_hex(sha1));
unlock_ref(lock);
return -1;
}
if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
error("Trying to write non-commit object %s to branch %s",
sha1_to_hex(sha1), lock->ref_name);
unlock_ref(lock);
return -1;
}
if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
write_in_full(lock->lock_fd, &term, 1) != 1
|| close_ref(lock) < 0) {
error("Couldn't write %s", lock->lk->filename);
unlock_ref(lock);
return -1;
}
invalidate_cached_refs();
if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
(strcmp(lock->ref_name, lock->orig_ref_name) &&
log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
unlock_ref(lock);
return -1;
}
if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
/*
* Special hack: If a branch is updated directly and HEAD
* points to it (may happen on the remote side of a push
* for example) then logically the HEAD reflog should be
* updated too.
* A generic solution implies reverse symref information,
* but finding all symrefs pointing to the given branch
* would be rather costly for this rare event (the direct
* update of a branch) to be worth it. So let's cheat and
* check with HEAD only which should cover 99% of all usage
* scenarios (even 100% of the default ones).
*/
unsigned char head_sha1[20];
int head_flag;
const char *head_ref;
head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
if (head_ref && (head_flag & REF_ISSYMREF) &&
!strcmp(head_ref, lock->ref_name))
log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
}
if (commit_ref(lock)) {
error("Couldn't set %s", lock->ref_name);
unlock_ref(lock);
return -1;
}
unlock_ref(lock);
return 0;
}
int create_symref(const char *ref_target, const char *refs_heads_master,
const char *logmsg)
{
const char *lockpath;
char ref[1000];
int fd, len, written;
char *git_HEAD = git_pathdup("%s", ref_target);
unsigned char old_sha1[20], new_sha1[20];
if (logmsg && read_ref(ref_target, old_sha1))
hashclr(old_sha1);
if (safe_create_leading_directories(git_HEAD) < 0)
return error("unable to create directory for %s", git_HEAD);
#ifndef NO_SYMLINK_HEAD
if (prefer_symlink_refs) {
unlink(git_HEAD);
if (!symlink(refs_heads_master, git_HEAD))
goto done;
fprintf(stderr, "no symlink - falling back to symbolic ref\n");
}
#endif
len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
if (sizeof(ref) <= len) {
error("refname too long: %s", refs_heads_master);
goto error_free_return;
}
lockpath = mkpath("%s.lock", git_HEAD);
fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
if (fd < 0) {
error("Unable to open %s for writing", lockpath);
goto error_free_return;
}
written = write_in_full(fd, ref, len);
if (close(fd) != 0 || written != len) {
error("Unable to write to %s", lockpath);
goto error_unlink_return;
}
if (rename(lockpath, git_HEAD) < 0) {
error("Unable to create %s", git_HEAD);
goto error_unlink_return;
}
if (adjust_shared_perm(git_HEAD)) {
error("Unable to fix permissions on %s", lockpath);
error_unlink_return:
unlink_or_warn(lockpath);
error_free_return:
free(git_HEAD);
return -1;
}
#ifndef NO_SYMLINK_HEAD
done:
#endif
if (logmsg && !read_ref(refs_heads_master, new_sha1))
log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
free(git_HEAD);
return 0;
}
static char *ref_msg(const char *line, const char *endp)
{
const char *ep;
line += 82;
ep = memchr(line, '\n', endp - line);
if (!ep)
ep = endp;
return xmemdupz(line, ep - line);
}
int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
{
const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
char *tz_c;
int logfd, tz, reccnt = 0;
struct stat st;
unsigned long date;
unsigned char logged_sha1[20];
void *log_mapped;
size_t mapsz;
logfile = git_path("logs/%s", ref);
logfd = open(logfile, O_RDONLY, 0);
if (logfd < 0)
die_errno("Unable to read log '%s'", logfile);
fstat(logfd, &st);
if (!st.st_size)
die("Log %s is empty.", logfile);
mapsz = xsize_t(st.st_size);
log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
logdata = log_mapped;
close(logfd);
lastrec = NULL;
rec = logend = logdata + st.st_size;
while (logdata < rec) {
reccnt++;
if (logdata < rec && *(rec-1) == '\n')
rec--;
lastgt = NULL;
while (logdata < rec && *(rec-1) != '\n') {
rec--;
if (*rec == '>')
lastgt = rec;
}
if (!lastgt)
die("Log %s is corrupt.", logfile);
date = strtoul(lastgt + 1, &tz_c, 10);
if (date <= at_time || cnt == 0) {
tz = strtoul(tz_c, NULL, 10);
if (msg)
*msg = ref_msg(rec, logend);
if (cutoff_time)
*cutoff_time = date;
if (cutoff_tz)
*cutoff_tz = tz;
if (cutoff_cnt)
*cutoff_cnt = reccnt - 1;
if (lastrec) {
if (get_sha1_hex(lastrec, logged_sha1))
die("Log %s is corrupt.", logfile);
if (get_sha1_hex(rec + 41, sha1))
die("Log %s is corrupt.", logfile);
if (hashcmp(logged_sha1, sha1)) {
warning("Log %s has gap after %s.",
logfile, show_date(date, tz, DATE_RFC2822));
}
}
else if (date == at_time) {
if (get_sha1_hex(rec + 41, sha1))
die("Log %s is corrupt.", logfile);
}
else {
if (get_sha1_hex(rec + 41, logged_sha1))
die("Log %s is corrupt.", logfile);
if (hashcmp(logged_sha1, sha1)) {
warning("Log %s unexpectedly ended on %s.",
logfile, show_date(date, tz, DATE_RFC2822));
}
}
munmap(log_mapped, mapsz);
return 0;
}
lastrec = rec;
if (cnt > 0)
cnt--;
}
rec = logdata;
while (rec < logend && *rec != '>' && *rec != '\n')
rec++;
if (rec == logend || *rec == '\n')
die("Log %s is corrupt.", logfile);
date = strtoul(rec + 1, &tz_c, 10);
tz = strtoul(tz_c, NULL, 10);
if (get_sha1_hex(logdata, sha1))
die("Log %s is corrupt.", logfile);
if (is_null_sha1(sha1)) {
if (get_sha1_hex(logdata + 41, sha1))
die("Log %s is corrupt.", logfile);
}
if (msg)
*msg = ref_msg(logdata, logend);
munmap(log_mapped, mapsz);
if (cutoff_time)
*cutoff_time = date;
if (cutoff_tz)
*cutoff_tz = tz;
if (cutoff_cnt)
*cutoff_cnt = reccnt;
return 1;
}
int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
{
const char *logfile;
FILE *logfp;
struct strbuf sb = STRBUF_INIT;
int ret = 0;
logfile = git_path("logs/%s", ref);
logfp = fopen(logfile, "r");
if (!logfp)
return -1;
if (ofs) {
struct stat statbuf;
if (fstat(fileno(logfp), &statbuf) ||
statbuf.st_size < ofs ||
fseek(logfp, -ofs, SEEK_END) ||
strbuf_getwholeline(&sb, logfp, '\n')) {
fclose(logfp);
strbuf_release(&sb);
return -1;
}
}
while (!strbuf_getwholeline(&sb, logfp, '\n')) {
unsigned char osha1[20], nsha1[20];
char *email_end, *message;
unsigned long timestamp;
int tz;
/* old SP new SP name <email> SP time TAB msg LF */
if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
!(email_end = strchr(sb.buf + 82, '>')) ||
email_end[1] != ' ' ||
!(timestamp = strtoul(email_end + 2, &message, 10)) ||
!message || message[0] != ' ' ||
(message[1] != '+' && message[1] != '-') ||
!isdigit(message[2]) || !isdigit(message[3]) ||
!isdigit(message[4]) || !isdigit(message[5]))
continue; /* corrupt? */
email_end[1] = '\0';
tz = strtol(message + 1, NULL, 10);
if (message[6] != '\t')
message += 6;
else
message += 7;
ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
cb_data);
if (ret)
break;
}
fclose(logfp);
strbuf_release(&sb);
return ret;
}
int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
{
return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
}
static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
{
DIR *dir = opendir(git_path("logs/%s", base));
int retval = 0;
if (dir) {
struct dirent *de;
int baselen = strlen(base);
char *log = xmalloc(baselen + 257);
memcpy(log, base, baselen);
if (baselen && base[baselen-1] != '/')
log[baselen++] = '/';
while ((de = readdir(dir)) != NULL) {
struct stat st;
int namelen;
if (de->d_name[0] == '.')
continue;
namelen = strlen(de->d_name);
if (namelen > 255)
continue;
if (has_extension(de->d_name, ".lock"))
continue;
memcpy(log + baselen, de->d_name, namelen+1);
if (stat(git_path("logs/%s", log), &st) < 0)
continue;
if (S_ISDIR(st.st_mode)) {
retval = do_for_each_reflog(log, fn, cb_data);
} else {
unsigned char sha1[20];
if (!resolve_ref(log, sha1, 0, NULL))
retval = error("bad ref for %s", log);
else
retval = fn(log, sha1, 0, cb_data);
}
if (retval)
break;
}
free(log);
closedir(dir);
}
else if (*base)
return errno;
return retval;
}
int for_each_reflog(each_ref_fn fn, void *cb_data)
{
return do_for_each_reflog("", fn, cb_data);
}
int update_ref(const char *action, const char *refname,
const unsigned char *sha1, const unsigned char *oldval,
int flags, enum action_on_err onerr)
{
static struct ref_lock *lock;
lock = lock_any_ref_for_update(refname, oldval, flags);
if (!lock) {
const char *str = "Cannot lock the ref '%s'.";
switch (onerr) {
case MSG_ON_ERR: error(str, refname); break;
case DIE_ON_ERR: die(str, refname); break;
case QUIET_ON_ERR: break;
}
return 1;
}
if (write_ref_sha1(lock, sha1, action) < 0) {
const char *str = "Cannot update the ref '%s'.";
switch (onerr) {
case MSG_ON_ERR: error(str, refname); break;
case DIE_ON_ERR: die(str, refname); break;
case QUIET_ON_ERR: break;
}
return 1;
}
return 0;
}
struct ref *find_ref_by_name(const struct ref *list, const char *name)
{
for ( ; list; list = list->next)
if (!strcmp(list->name, name))
return (struct ref *)list;
return NULL;
}
/*
* generate a format suitable for scanf from a ref_rev_parse_rules
* rule, that is replace the "%.*s" spec with a "%s" spec
*/
static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
{
char *spec;
spec = strstr(rule, "%.*s");
if (!spec || strstr(spec + 4, "%.*s"))
die("invalid rule in ref_rev_parse_rules: %s", rule);
/* copy all until spec */
strncpy(scanf_fmt, rule, spec - rule);
scanf_fmt[spec - rule] = '\0';
/* copy new spec */
strcat(scanf_fmt, "%s");
/* copy remaining rule */
strcat(scanf_fmt, spec + 4);
return;
}
char *shorten_unambiguous_ref(const char *ref, int strict)
{
int i;
static char **scanf_fmts;
static int nr_rules;
char *short_name;
/* pre generate scanf formats from ref_rev_parse_rules[] */
if (!nr_rules) {
size_t total_len = 0;
/* the rule list is NULL terminated, count them first */
for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
/* no +1 because strlen("%s") < strlen("%.*s") */
total_len += strlen(ref_rev_parse_rules[nr_rules]);
scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
total_len = 0;
for (i = 0; i < nr_rules; i++) {
scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
+ total_len;
gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
total_len += strlen(ref_rev_parse_rules[i]);
}
}
/* bail out if there are no rules */
if (!nr_rules)
return xstrdup(ref);
/* buffer for scanf result, at most ref must fit */
short_name = xstrdup(ref);
/* skip first rule, it will always match */
for (i = nr_rules - 1; i > 0 ; --i) {
int j;
int rules_to_fail = i;
int short_name_len;
if (1 != sscanf(ref, scanf_fmts[i], short_name))
continue;
short_name_len = strlen(short_name);
/*
* in strict mode, all (except the matched one) rules
* must fail to resolve to a valid non-ambiguous ref
*/
if (strict)
rules_to_fail = nr_rules;
/*
* check if the short name resolves to a valid ref,
* but use only rules prior to the matched one
*/
for (j = 0; j < rules_to_fail; j++) {
const char *rule = ref_rev_parse_rules[j];
unsigned char short_objectname[20];
char refname[PATH_MAX];
/* skip matched rule */
if (i == j)
continue;
/*
* the short name is ambiguous, if it resolves
* (with this previous rule) to a valid ref
* read_ref() returns 0 on success
*/
mksnpath(refname, sizeof(refname),
rule, short_name_len, short_name);
if (!read_ref(refname, short_objectname))
break;
}
/*
* short name is non-ambiguous if all previous rules
* haven't resolved to a valid ref
*/
if (j == rules_to_fail)
return short_name;
}
free(short_name);
return xstrdup(ref);
}