branch: description for orphan branch errors

In bcfc82bd48 (branch: description for non-existent branch errors,
2022-10-08) we checked the HEAD in the current worktree to detect if the
branch to operate with is an orphan branch, so as to avoid the confusing
error: "No branch named...".

If we are asked to operate with an orphan branch in a different working
tree than the current one, we need to check the HEAD in that different
working tree.

Let's extend the check we did in bcfc82bd48, to check the HEADs in all
worktrees linked to the current repository, using the helper introduced
in 31ad6b61bd (branch: add branch_checked_out() helper, 2022-06-15).

The helper, branch_checked_out(), does its work obtaining internally a
list of worktrees linked to the current repository.  Obtaining that list
is not a lightweight work because it implies disk access.

In copy_or_rename_branch() we already have a list of worktrees.  Let's
use that already obtained list, and avoid using here the helper.

Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/branch.c b/builtin/branch.c
index bac67c27d5e6106ebecec04002aa16fec6936e79..90dcbb0c6e779668dc8662761b65030b1f61bd04 100644 (file)
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -538,13 +538,15 @@ static int replace_each_worktree_head_symref(struct worktree **worktrees,
        return ret;
 }
 
+#define IS_HEAD 1
+
 static void copy_or_rename_branch(const char *oldname, const char *newname, int copy, int force)
 {
        struct strbuf oldref = STRBUF_INIT, newref = STRBUF_INIT, logmsg = STRBUF_INIT;
        struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
        const char *interpreted_oldname = NULL;
        const char *interpreted_newname = NULL;
-       int recovery = 0;
+       int recovery = 0, oldref_usage = 0;
        struct worktree **worktrees = get_worktrees();
 
        if (strbuf_check_branch_ref(&oldref, oldname)) {
@@ -558,8 +560,17 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
                        die(_("Invalid branch name: '%s'"), oldname);
        }
 
-       if ((copy || strcmp(head, oldname)) && !ref_exists(oldref.buf)) {
-               if (copy && !strcmp(head, oldname))
+       for (int i = 0; worktrees[i]; i++) {
+               struct worktree *wt = worktrees[i];
+
+               if (wt->head_ref && !strcmp(oldref.buf, wt->head_ref)) {
+                       oldref_usage |= IS_HEAD;
+                       break;
+               }
+       }
+
+       if ((copy || !(oldref_usage & IS_HEAD)) && !ref_exists(oldref.buf)) {
+               if (oldref_usage & IS_HEAD)
                        die(_("No commit on branch '%s' yet."), oldname);
                else
                        die(_("No branch named '%s'."), oldname);
@@ -838,7 +849,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 
                strbuf_addf(&branch_ref, "refs/heads/%s", branch_name);
                if (!ref_exists(branch_ref.buf))
-                       error((!argc || !strcmp(head, branch_name))
+                       error((!argc || branch_checked_out(branch_ref.buf))
                              ? _("No commit on branch '%s' yet.")
                              : _("No branch named '%s'."),
                              branch_name);
@@ -883,7 +894,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
                }
 
                if (!ref_exists(branch->refname)) {
-                       if (!argc || !strcmp(head, branch->name))
+                       if (!argc || branch_checked_out(branch->refname))
                                die(_("No commit on branch '%s' yet."), branch->name);
                        die(_("branch '%s' does not exist"), branch->name);
                }

diff --git a/t/t3202-show-branch.sh b/t/t3202-show-branch.sh
index ea7cfd1951d8b2173c8fe13f1bc307ff9e7cfa1c..be20ebe1d5c673bc04160dd95704b2b0f722ae26 100755 (executable)
--- a/t/t3202-show-branch.sh
+++ b/t/t3202-show-branch.sh
@@ -221,4 +221,22 @@ test_expect_success 'fatal descriptions on non-existent branch' '
        test_cmp expect actual
 '
 
+test_expect_success 'error descriptions on orphan branch' '
+       test_when_finished git worktree remove -f wt &&
+       git worktree add wt --detach &&
+       git -C wt checkout --orphan orphan-branch &&
+       test_branch_op_in_wt() {
+               test_orphan_error() {
+                       test_must_fail git $* 2>actual &&
+                       test_i18ngrep "No commit on branch .orphan-branch. yet.$" actual
+               } &&
+               test_orphan_error -C wt branch $1 $2 &&                # implicit branch
+               test_orphan_error -C wt branch $1 orphan-branch $2 &&  # explicit branch
+               test_orphan_error branch $1 orphan-branch $2           # different worktree
+       } &&
+       test_branch_op_in_wt --edit-description &&
+       test_branch_op_in_wt --set-upstream-to=ne &&
+       test_branch_op_in_wt -c new-branch
+'
+
 test_done