completion: return the index of found word from __git_find_on_cmdline()

When using the __git_find_on_cmdline() helper function so far we've
only been interested in which one of a set of words appear on the
command line.  To complete options for some of 'git worktree's
subcommands in the following patches we'll need not only that, but the
index of that word on the command line as well.

Extend __git_find_on_cmdline() to optionally show the index of the
found word on the command line (IOW in the $words array) when the
'--show-idx' option is given.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index a1762f9d58..d988e516d7 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -1392,6 +1392,35 @@ test_expect_success '__git_find_on_cmdline - no match' '
 	test_must_be_empty actual
 '
 
+test_expect_success '__git_find_on_cmdline - single match with index' '
+	echo "3 list" >expect &&
+	(
+		words=(git command --opt list) &&
+		cword=${#words[@]} &&
+		__git_find_on_cmdline --show-idx "add list remove" >actual
+	) &&
+	test_cmp expect actual
+'
+
+test_expect_success '__git_find_on_cmdline - multiple matches with index' '
+	echo "4 remove" >expect &&
+	(
+		words=(git command -o --opt remove list add) &&
+		cword=${#words[@]} &&
+		__git_find_on_cmdline --show-idx "add list remove" >actual
+	) &&
+	test_cmp expect actual
+'
+
+test_expect_success '__git_find_on_cmdline - no match with index' '
+	(
+		words=(git command --opt branch) &&
+		cword=${#words[@]} &&
+		__git_find_on_cmdline --show-idx "add list remove" >actual
+	) &&
+	test_must_be_empty actual
+'
+
 test_expect_success '__git_get_config_variables' '
 	cat >expect <<-EOF &&
 	name-1