gc: do not explode objects which will be immediately pruned

diff --git a/builtin/branch.c b/builtin/branch.c
index e1e486e4c51194e09df3779be254cb72855d1103..d8cccf725d3fab24ad585a26629373fc987bb3f8 100644 (file)
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -104,6 +104,7 @@ static int branch_merged(int kind, const char *name,
         */
        struct commit *reference_rev = NULL;
        const char *reference_name = NULL;
+       void *reference_name_to_free = NULL;
        int merged;
 
        if (kind == REF_LOCAL_BRANCH) {
@@ -114,11 +115,9 @@ static int branch_merged(int kind, const char *name,
                    branch->merge &&
                    branch->merge[0] &&
                    branch->merge[0]->dst &&
-                   (reference_name =
-                    resolve_ref(branch->merge[0]->dst, sha1, 1, NULL)) != NULL) {
-                       reference_name = xstrdup(reference_name);
+                   (reference_name = reference_name_to_free =
+                    resolve_refdup(branch->merge[0]->dst, sha1, 1, NULL)) != NULL)
                        reference_rev = lookup_commit_reference(sha1);
-               }
        }
        if (!reference_rev)
                reference_rev = head_rev;
@@ -143,7 +142,7 @@ static int branch_merged(int kind, const char *name,
                                "         '%s', even though it is merged to HEAD."),
                                name, reference_name);
        }
-       free((char *)reference_name);
+       free(reference_name_to_free);
        return merged;
 }
 
@@ -253,7 +252,7 @@ static char *resolve_symref(const char *src, const char *prefix)
        int flag;
        const char *dst, *cp;
 
-       dst = resolve_ref(src, sha1, 0, &flag);
+       dst = resolve_ref_unsafe(src, sha1, 0, &flag);
        if (!(dst && (flag & REF_ISSYMREF)))
                return NULL;
        if (prefix && (cp = skip_prefix(dst, prefix)))
@@ -531,6 +530,10 @@ static int print_ref_list(int kinds, int detached, int verbose, int abbrev, stru
        if (merge_filter != NO_FILTER) {
                struct commit *filter;
                filter = lookup_commit_reference_gently(merge_filter_ref, 0);
+               if (!filter)
+                       die("object '%s' does not point to a commit",
+                           sha1_to_hex(merge_filter_ref));
+
                filter->object.flags |= UNINTERESTING;
                add_pending_object(&ref_list.revs,
                                   (struct object *) filter, "");
@@ -570,6 +573,7 @@ static void rename_branch(const char *oldname, const char *newname, int force)
        struct strbuf oldref = STRBUF_INIT, newref = STRBUF_INIT, logmsg = STRBUF_INIT;
        struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
        int recovery = 0;
+       int clobber_head_ok;
 
        if (!oldname)
                die(_("cannot rename the current branch while not on any."));
@@ -585,7 +589,13 @@ static void rename_branch(const char *oldname, const char *newname, int force)
                        die(_("Invalid branch name: '%s'"), oldname);
        }
 
-       validate_new_branchname(newname, &newref, force, 0);
+       /*
+        * A command like "git branch -M currentbranch currentbranch" cannot
+        * cause the worktree to become inconsistent with HEAD, so allow it.
+        */
+       clobber_head_ok = !strcmp(oldname, newname);
+
+       validate_new_branchname(newname, &newref, force, clobber_head_ok);
 
        strbuf_addf(&logmsg, "Branch: renamed %s to %s",
                 oldref.buf, newref.buf);
@@ -731,10 +741,9 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 
        track = git_branch_track;
 
-       head = resolve_ref("HEAD", head_sha1, 0, NULL);
+       head = resolve_refdup("HEAD", head_sha1, 0, NULL);
        if (!head)
                die(_("Failed to resolve HEAD as a valid ref."));
-       head = xstrdup(head);
        if (!strcmp(head, "HEAD")) {
                detached = 1;
        } else {
@@ -763,6 +772,8 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
                                      with_commit, argv);
        else if (edit_description) {
                const char *branch_name;
+               struct strbuf branch_ref = STRBUF_INIT;
+
                if (detached)
                        die("Cannot give description to detached HEAD");
                if (!argc)
@@ -771,6 +782,19 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
                        branch_name = argv[0];
                else
                        usage_with_options(builtin_branch_usage, options);
+
+               strbuf_addf(&branch_ref, "refs/heads/%s", branch_name);
+               if (!ref_exists(branch_ref.buf)) {
+                       strbuf_release(&branch_ref);
+
+                       if (!argc)
+                               return error("No commit on branch '%s' yet.",
+                                            branch_name);
+                       else
+                               return error("No such branch '%s'.", branch_name);
+               }
+               strbuf_release(&branch_ref);
+
                if (edit_branch_description(branch_name))
                        return 1;
        } else if (rename) {
@@ -784,7 +808,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
                if (kinds != REF_LOCAL_BRANCH)
                        die(_("-a and -r options to 'git branch' do not make sense with a branch name"));
                create_branch(head, argv[0], (argc == 2) ? argv[1] : head,
-                             force_create, reflog, track);
+                             force_create, reflog, 0, track);
        } else
                usage_with_options(builtin_branch_usage, options);