branch: add worktree info on verbose output

To display worktree path for refs checked out in a linked worktree

Signed-off-by: Nickolai Belakovski <nbelakovski@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-branch.txt

@@ -172,8 +172,10 @@ This option is only applicable in non-verbose mode.
 	When in list mode,
 	show sha1 and commit subject line for each head, along with
 	relationship to upstream branch (if any). If given twice, print
-	the name of the upstream branch, as well (see also `git remote
+	the path of the linked worktree (if any) and the name of the upstream
-	show <remote>`).
+	branch, as well (see also `git remote show <remote>`).  Note that the
+	current worktree's HEAD will not have its path printed (it will always
+	be your current directory).
 
 -q::
 --quiet::

builtin/branch.c

@@ -367,9 +367,13 @@ static char *build_format(struct ref_filter *filter, int maxwidth, const char *r
 		strbuf_addf(&local, " %s ", obname.buf);
 
 		if (filter->verbose > 1)
+		{
+			strbuf_addf(&local, "%%(if:notequals=*)%%(HEAD)%%(then)%%(if)%%(worktreepath)%%(then)(%s%%(worktreepath)%s) %%(end)%%(end)",
+				    branch_get_color(BRANCH_COLOR_WORKTREE), branch_get_color(BRANCH_COLOR_RESET));
 			strbuf_addf(&local, "%%(if)%%(upstream)%%(then)[%s%%(upstream:short)%s%%(if)%%(upstream:track)"
 				    "%%(then): %%(upstream:track,nobracket)%%(end)] %%(end)%%(contents:subject)",
 				    branch_get_color(BRANCH_COLOR_UPSTREAM), branch_get_color(BRANCH_COLOR_RESET));
+		}
 		else
 			strbuf_addf(&local, "%%(if)%%(upstream:track)%%(then)%%(upstream:track) %%(end)%%(contents:subject)");
 

t/t3203-branch-output.sh

@@ -328,4 +328,23 @@ test_expect_success '--color overrides auto-color' '
 	test_cmp expect.color actual
 '
 
+test_expect_success 'verbose output lists worktree path' '
+	one=$(git rev-parse --short HEAD) &&
+	two=$(git rev-parse --short master) &&
+	cat >expect <<-EOF &&
+	* (HEAD detached from fromtag) $one one
+	  ambiguous                    $one one
+	  branch-one                   $two two
+	+ branch-two                   $one ($(pwd)/worktree_dir) one
+	  master                       $two two
+	  ref-to-branch                $two two
+	  ref-to-remote                $two two
+	EOF
+	git worktree add worktree_dir branch-two &&
+	git branch -vv >actual &&
+	rm -r worktree_dir &&
+	git worktree prune &&
+	test_i18ncmp expect actual
+'
+
 test_done