cherry-pick: Suggest a better method to retain authorship

diff --git a/sha1_name.c b/sha1_name.c
index d77f77097f6e00615732c5e6d50a2c594bef4311..0781477a71ac4d76a1b8783868d6649cae7f8507 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -267,7 +267,7 @@ int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
        return refs_found;
 }
 
-static int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
+int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
 {
        const char **p;
        int logs_found = 0;
@@ -275,16 +275,29 @@ static int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
        *log = NULL;
        for (p = ref_fmt; *p; p++) {
                struct stat st;
-               char *path = mkpath(*p, len, str);
+               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)) {
-                       if (!logs_found++) {
-                               *log = xstrdup(path);
-                               resolve_ref(path, sha1, 0, NULL);
-                       }
-                       if (!warn_ambiguous_refs)
-                               break;
+                   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;
 }
@@ -564,6 +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"
@@ -587,6 +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])