t5520: test work tree fast-forward when fetch updates head
[gitweb.git] / builtin / merge.c
index 9f9853876bb3345a1d7e9746c35f13ffbf06498f..67fbfafa027bfb8dbb7410626957a8975b89c4f5 100644 (file)
@@ -505,28 +505,6 @@ static void merge_name(const char *remote, struct strbuf *msg)
                strbuf_release(&truname);
        }
 
-       if (!strcmp(remote, "FETCH_HEAD") &&
-                       !access(git_path("FETCH_HEAD"), R_OK)) {
-               const char *filename;
-               FILE *fp;
-               struct strbuf line = STRBUF_INIT;
-               char *ptr;
-
-               filename = git_path("FETCH_HEAD");
-               fp = fopen(filename, "r");
-               if (!fp)
-                       die_errno(_("could not open '%s' for reading"),
-                                 filename);
-               strbuf_getline(&line, fp, '\n');
-               fclose(fp);
-               ptr = strstr(line.buf, "\tnot-for-merge\t");
-               if (ptr)
-                       strbuf_remove(&line, ptr-line.buf+1, 13);
-               strbuf_addbuf(msg, &line);
-               strbuf_release(&line);
-               goto cleanup;
-       }
-
        if (remote_head->util) {
                struct merge_remote_desc *desc;
                desc = merge_remote_util(remote_head);
@@ -1090,6 +1068,60 @@ static void prepare_merge_message(struct strbuf *merge_names, struct strbuf *mer
                strbuf_setlen(merge_msg, merge_msg->len - 1);
 }
 
+static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge_names)
+{
+       const char *filename;
+       int fd, pos, npos;
+       struct strbuf fetch_head_file = STRBUF_INIT;
+
+       if (!merge_names)
+               merge_names = &fetch_head_file;
+
+       filename = git_path("FETCH_HEAD");
+       fd = open(filename, O_RDONLY);
+       if (fd < 0)
+               die_errno(_("could not open '%s' for reading"), filename);
+
+       if (strbuf_read(merge_names, fd, 0) < 0)
+               die_errno(_("could not read '%s'"), filename);
+       if (close(fd) < 0)
+               die_errno(_("could not close '%s'"), filename);
+
+       for (pos = 0; pos < merge_names->len; pos = npos) {
+               unsigned char sha1[20];
+               char *ptr;
+               struct commit *commit;
+
+               ptr = strchr(merge_names->buf + pos, '\n');
+               if (ptr)
+                       npos = ptr - merge_names->buf + 1;
+               else
+                       npos = merge_names->len;
+
+               if (npos - pos < 40 + 2 ||
+                   get_sha1_hex(merge_names->buf + pos, sha1))
+                       commit = NULL; /* bad */
+               else if (memcmp(merge_names->buf + pos + 40, "\t\t", 2))
+                       continue; /* not-for-merge */
+               else {
+                       char saved = merge_names->buf[pos + 40];
+                       merge_names->buf[pos + 40] = '\0';
+                       commit = get_merge_parent(merge_names->buf + pos);
+                       merge_names->buf[pos + 40] = saved;
+               }
+               if (!commit) {
+                       if (ptr)
+                               *ptr = '\0';
+                       die("not something we can merge in %s: %s",
+                           filename, merge_names->buf + pos);
+               }
+               remotes = &commit_list_insert(commit, remotes)->next;
+       }
+
+       if (merge_names == &fetch_head_file)
+               strbuf_release(&fetch_head_file);
+}
+
 static struct commit_list *collect_parents(struct commit *head_commit,
                                           int *head_subsumed,
                                           int argc, const char **argv,
@@ -1098,28 +1130,36 @@ static struct commit_list *collect_parents(struct commit *head_commit,
        int i;
        struct commit_list *remoteheads = NULL;
        struct commit_list **remotes = &remoteheads;
+       struct strbuf merge_names = STRBUF_INIT, *autogen = NULL;
+
+       if (merge_msg && (!have_message || shortlog_len))
+               autogen = &merge_names;
 
        if (head_commit)
                remotes = &commit_list_insert(head_commit, remotes)->next;
-       for (i = 0; i < argc; i++) {
-               struct commit *commit = get_merge_parent(argv[i]);
-               if (!commit)
-                       help_unknown_ref(argv[i], "merge",
-                                        "not something we can merge");
-               remotes = &commit_list_insert(commit, remotes)->next;
-       }
 
-       remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
-
-       if (merge_msg &&
-           (!have_message || shortlog_len)) {
-               struct strbuf merge_names = STRBUF_INIT;
-               struct commit_list *p;
+       if (argc == 1 && !strcmp(argv[0], "FETCH_HEAD")) {
+               handle_fetch_head(remotes, autogen);
+               remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
+       } else {
+               for (i = 0; i < argc; i++) {
+                       struct commit *commit = get_merge_parent(argv[i]);
+                       if (!commit)
+                               help_unknown_ref(argv[i], "merge",
+                                                "not something we can merge");
+                       remotes = &commit_list_insert(commit, remotes)->next;
+               }
+               remoteheads = reduce_parents(head_commit, head_subsumed, remoteheads);
+               if (autogen) {
+                       struct commit_list *p;
+                       for (p = remoteheads; p; p = p->next)
+                               merge_name(merge_remote_util(p->item)->name, autogen);
+               }
+       }
 
-               for (p = remoteheads; p; p = p->next)
-                       merge_name(merge_remote_util(p->item)->name, &merge_names);
-               prepare_merge_message(&merge_names, merge_msg);
-               strbuf_release(&merge_names);
+       if (autogen) {
+               prepare_merge_message(autogen, merge_msg);
+               strbuf_release(autogen);
        }
 
        return remoteheads;
@@ -1259,6 +1299,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
         */
        if (!have_message &&
            is_old_style_invocation(argc, argv, head_commit->object.sha1)) {
+               warning("old-style 'git merge <msg> HEAD <commit>' is deprecated.");
                strbuf_addstr(&merge_msg, argv[0]);
                head_arg = argv[1];
                argv += 2;