cherry-pick: Suggest a better method to retain authorship
[gitweb.git] / sha1_name.c
index 6ffee22081aee3fc7b27b9ccc93c4c721652ec4b..0781477a71ac4d76a1b8783868d6649cae7f8507 100644 (file)
@@ -235,55 +235,106 @@ static int ambiguous_path(const char *path, int len)
        return slash;
 }
 
+static const char *ref_fmt[] = {
+       "%.*s",
+       "refs/%.*s",
+       "refs/tags/%.*s",
+       "refs/heads/%.*s",
+       "refs/remotes/%.*s",
+       "refs/remotes/%.*s/HEAD",
+       NULL
+};
+
+int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
+{
+       const char **p, *r;
+       int refs_found = 0;
+
+       *ref = NULL;
+       for (p = ref_fmt; *p; p++) {
+               unsigned char sha1_from_ref[20];
+               unsigned char *this_result;
+
+               this_result = refs_found ? sha1_from_ref : sha1;
+               r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL);
+               if (r) {
+                       if (!refs_found++)
+                               *ref = xstrdup(r);
+                       if (!warn_ambiguous_refs)
+                               break;
+               }
+       }
+       return refs_found;
+}
+
+int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
+{
+       const char **p;
+       int logs_found = 0;
+
+       *log = NULL;
+       for (p = ref_fmt; *p; p++) {
+               struct stat st;
+               unsigned char hash[20];
+               char path[PATH_MAX];
+               const char *ref, *it;
+
+               strcpy(path, mkpath(*p, len, str));
+               ref = resolve_ref(path, hash, 0, NULL);
+               if (!ref)
+                       continue;
+               if (!stat(git_path("logs/%s", path), &st) &&
+                   S_ISREG(st.st_mode))
+                       it = path;
+               else if (strcmp(ref, path) &&
+                        !stat(git_path("logs/%s", ref), &st) &&
+                        S_ISREG(st.st_mode))
+                       it = ref;
+               else
+                       continue;
+               if (!logs_found++) {
+                       *log = xstrdup(it);
+                       hashcpy(sha1, hash);
+               }
+               if (!warn_ambiguous_refs)
+                       break;
+       }
+       return logs_found;
+}
+
 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 {
-       static const char *fmt[] = {
-               "%.*s",
-               "refs/%.*s",
-               "refs/tags/%.*s",
-               "refs/heads/%.*s",
-               "refs/remotes/%.*s",
-               "refs/remotes/%.*s/HEAD",
-               NULL
-       };
        static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
-       const char **p, *pathname;
-       char *real_path = NULL;
-       int refs_found = 0, am;
-       unsigned long at_time = (unsigned long)-1;
-       unsigned char *this_result;
-       unsigned char sha1_from_ref[20];
+       char *real_ref = NULL;
+       int refs_found = 0;
+       int at, reflog_len;
 
        if (len == 40 && !get_sha1_hex(str, sha1))
                return 0;
 
-       /* At a given period of time? "@{2 hours ago}" */
-       for (am = 1; am < len - 1; am++) {
-               if (str[am] == '@' && str[am+1] == '{' && str[len-1] == '}') {
-                       int date_len = len - am - 3;
-                       char *date_spec = xmalloc(date_len + 1);
-                       strlcpy(date_spec, str + am + 2, date_len + 1);
-                       at_time = approxidate(date_spec);
-                       free(date_spec);
-                       len = am;
-                       break;
+       /* basic@{time or number} format to query ref-log */
+       reflog_len = at = 0;
+       if (str[len-1] == '}') {
+               for (at = 0; at < len - 1; at++) {
+                       if (str[at] == '@' && str[at+1] == '{') {
+                               reflog_len = (len-1) - (at+2);
+                               len = at;
+                               break;
+                       }
                }
        }
 
        /* Accept only unambiguous ref paths. */
-       if (ambiguous_path(str, len))
+       if (len && ambiguous_path(str, len))
                return -1;
 
-       for (p = fmt; *p; p++) {
-               this_result = refs_found ? sha1_from_ref : sha1;
-               pathname = resolve_ref(git_path(*p, len, str), this_result, 1);
-               if (pathname) {
-                       if (!refs_found++)
-                               real_path = xstrdup(pathname);
-                       if (!warn_ambiguous_refs)
-                               break;
-               }
-       }
+       if (!len && reflog_len) {
+               /* allow "@{...}" to mean the current branch reflog */
+               refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
+       } else if (reflog_len)
+               refs_found = dwim_log(str, len, sha1, &real_ref);
+       else
+               refs_found = dwim_ref(str, len, sha1, &real_ref);
 
        if (!refs_found)
                return -1;
@@ -291,14 +342,39 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
        if (warn_ambiguous_refs && refs_found > 1)
                fprintf(stderr, warning, len, str);
 
-       if (at_time != (unsigned long)-1) {
-               read_ref_at(
-                       real_path + strlen(git_path(".")) - 1,
-                       at_time,
-                       sha1);
+       if (reflog_len) {
+               int nth, i;
+               unsigned long at_time;
+               unsigned long co_time;
+               int co_tz, co_cnt;
+
+               /* Is it asking for N-th entry, or approxidate? */
+               for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
+                       char ch = str[at+2+i];
+                       if ('0' <= ch && ch <= '9')
+                               nth = nth * 10 + ch - '0';
+                       else
+                               nth = -1;
+               }
+               if (0 <= nth)
+                       at_time = 0;
+               else
+                       at_time = approxidate(str + at + 2);
+               if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
+                               &co_time, &co_tz, &co_cnt)) {
+                       if (at_time)
+                               fprintf(stderr,
+                                       "warning: Log for '%.*s' only goes "
+                                       "back to %s.\n", len, str,
+                                       show_rfc2822_date(co_time, co_tz));
+                       else
+                               fprintf(stderr,
+                                       "warning: Log for '%.*s' only has "
+                                       "%d entries.\n", len, str, co_cnt);
+               }
        }
 
-       free(real_path);
+       free(real_ref);
        return 0;
 }
 
@@ -501,6 +577,62 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1)
        return get_short_sha1(name, len, sha1, 0);
 }
 
+static int handle_one_ref(const char *path,
+               const unsigned char *sha1, int flag, void *cb_data)
+{
+       struct commit_list **list = cb_data;
+       struct object *object = parse_object(sha1);
+       if (!object)
+               return 0;
+       if (object->type == OBJ_TAG)
+               object = deref_tag(object, path, strlen(path));
+       if (object->type != OBJ_COMMIT)
+               return 0;
+       insert_by_date((struct commit *)object, list);
+       return 0;
+}
+
+/*
+ * This interprets names like ':/Initial revision of "git"' by searching
+ * through history and returning the first commit whose message starts
+ * with the given string.
+ *
+ * For future extension, ':/!' is reserved. If you want to match a message
+ * beginning with a '!', you have to repeat the exclamation mark.
+ */
+
+#define ONELINE_SEEN (1u<<20)
+int get_sha1_oneline(const char *prefix, unsigned char *sha1)
+{
+       struct commit_list *list = NULL, *backup = NULL, *l;
+       struct commit *commit;
+
+       if (prefix[0] == '!') {
+               if (prefix[1] != '!')
+                       die ("Invalid search pattern: %s", prefix);
+               prefix++;
+       }
+       if (!save_commit_buffer)
+               return error("Could not expand oneline-name.");
+       for_each_ref(handle_one_ref, &list);
+       for (l = list; l; l = l->next)
+               commit_list_insert(l->item, &backup);
+       while ((commit = pop_most_recent_commit(&list, ONELINE_SEEN))) {
+               char *p;
+               parse_object(commit->object.sha1);
+               if (!commit->buffer || !(p = strstr(commit->buffer, "\n\n")))
+                       continue;
+               if (!prefixcmp(p + 2, prefix)) {
+                       hashcpy(sha1, commit->object.sha1);
+                       break;
+               }
+       }
+       free_commit_list(list);
+       for (l = backup; l; l = l->next)
+               clear_commit_marks(l->item, ONELINE_SEEN);
+       return commit == NULL;
+}
+
 /*
  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
  * notably "xyz^" for "parent of xyz"
@@ -524,6 +656,8 @@ int get_sha1(const char *name, unsigned char *sha1)
                int stage = 0;
                struct cache_entry *ce;
                int pos;
+               if (namelen > 2 && name[1] == '/')
+                       return get_sha1_oneline(name + 2, sha1);
                if (namelen < 3 ||
                    name[2] != ':' ||
                    name[1] < '0' || '3' < name[1])