[PATCH v2 1/3] completion: bash: support recursive aliases

[Felipe Contreras <felipe.contreras@gmail.com>]

It is possible to have a recursive aliases like:

  l = log --oneline
  lg = l --graph

So the completion should detect such aliases as well.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 contrib/completion/git-completion.bash | 48 ++++++++++++++++----------
 t/t9902-completion.sh                  | 19 ++++++++++
 2 files changed, 48 insertions(+), 19 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 36f5a91c7a..59ced25641 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1121,26 +1121,36 @@ __git_pretty_aliases ()
 # __git_aliased_command requires 1 argument
 __git_aliased_command ()
 {
-	local word cmdline=$(__git config --get "alias.$1")
-	for word in $cmdline; do
-		case "$word" in
-		\!gitk|gitk)
-			echo "gitk"
-			return
-			;;
-		\!*)	: shell command alias ;;
-		-*)	: option ;;
-		*=*)	: setting env ;;
-		git)	: git itself ;;
-		\(\))   : skip parens of shell function definition ;;
-		{)	: skip start of shell helper function ;;
-		:)	: skip null command ;;
-		\'*)	: skip opening quote after sh -c ;;
-		*)
-			echo "$word"
-			return
-		esac
+	local cur=$1 last word cmdline
+
+	while [[ "$cur" != "$last" ]]; do
+		cmdline=$(__git config --get "alias.$cur")
+		last=$cur
+
+		for word in $cmdline; do
+			case "$word" in
+			\!gitk|gitk)
+				cur="gitk"
+				break
+				;;
+			\!*)	: shell command alias ;;
+			-*)	: option ;;
+			*=*)	: setting env ;;
+			git)	: git itself ;;
+			\(\))   : skip parens of shell function definition ;;
+			{)	: skip start of shell helper function ;;
+			:)	: skip null command ;;
+			\'*)	: skip opening quote after sh -c ;;
+			*)
+				cur="$word"
+				break
+			esac
+		done
 	done
+
+	if [[ "$cur" != "$1" ]]; then
+		echo "$cur"
+	fi
 }
 
 # Check whether one of the given words is present on the command line,
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
index 4e943393cf..0e2db6e7fa 100755
--- a/t/t9902-completion.sh
+++ b/t/t9902-completion.sh
@@ -2195,6 +2195,25 @@ test_expect_success 'complete files' '
 	test_completion "git add mom" "momified"
 '
 
+test_expect_success "simple alias" '
+	test_config alias.co checkout &&
+	test_completion "git co m" <<-\EOF
+	master Z
+	mybranch Z
+	mytag Z
+	EOF
+'
+
+test_expect_success "recursive alias" '
+	test_config alias.co checkout &&
+	test_config alias.cod "co --detached" &&
+	test_completion "git cod m" <<-\EOF
+	master Z
+	mybranch Z
+	mytag Z
+	EOF
+'
+
 test_expect_success "completion uses <cmd> completion for alias: !sh -c 'git <cmd> ...'" '
 	test_config alias.co "!sh -c '"'"'git checkout ...'"'"'" &&
 	test_completion "git co m" <<-\EOF
-- 
2.29.2