completion: refactor existence checks for pseudorefs

In preparation for the reftable backend, this commit introduces a
'__git_pseudoref_exists' function that continues to use 'test -f' to
determine whether a given pseudoref exists in the local filesystem.

Signed-off-by: Stan Hu <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: stanhu

contrib/completion/git-completion.bash

@@ -122,6 +122,15 @@ __git ()
 		${__git_dir:+--git-dir="$__git_dir"} "$@" 2>/dev/null
 }
 
+# Runs git in $__git_repo_path to determine whether a pseudoref exists.
+# 1: The pseudo-ref to search
+__git_pseudoref_exists ()
+{
+	local ref=$1
+
+	[ -f "$__git_repo_path/$ref" ]
+}
+
 # Removes backslash escaping, single quotes and double quotes from a word,
 # stores the result in the variable $dequoted_word.
 # 1: The word to dequote.
@@ -1625,7 +1634,7 @@ __git_cherry_pick_inprogress_options=$__git_sequencer_inprogress_options
 _git_cherry_pick ()
 {
 	__git_find_repo_path
-	if [ -f "$__git_repo_path"/CHERRY_PICK_HEAD ]; then
+	if __git_pseudoref_exists CHERRY_PICK_HEAD; then
 		__gitcomp "$__git_cherry_pick_inprogress_options"
 		return
 	fi
@@ -2067,7 +2076,7 @@ _git_log ()
 	__git_find_repo_path
 
 	local merge=""
-	if [ -f "$__git_repo_path/MERGE_HEAD" ]; then
+	if __git_pseudoref_exists MERGE_HEAD; then
 		merge="--merge"
 	fi
 	case "$prev,$cur" in
@@ -2934,6 +2943,7 @@ _git_reset ()
 
 _git_restore ()
 {
+	__git_find_repo_path
 	case "$prev" in
 	-s)
 		__git_complete_refs
@@ -2952,7 +2962,7 @@ _git_restore ()
 		__gitcomp_builtin restore
 		;;
 	*)
-		if __git rev-parse --verify --quiet HEAD >/dev/null; then
+		if __git_pseudoref_exists HEAD; then
 			__git_complete_index_file "--modified"
 		fi
 	esac
@@ -2963,7 +2973,7 @@ __git_revert_inprogress_options=$__git_sequencer_inprogress_options
 _git_revert ()
 {
 	__git_find_repo_path
-	if [ -f "$__git_repo_path"/REVERT_HEAD ]; then
+	if __git_pseudoref_exists REVERT_HEAD; then
 		__gitcomp "$__git_revert_inprogress_options"
 		return
 	fi
@@ -3592,7 +3602,7 @@ __gitk_main ()
 	__git_find_repo_path
 
 	local merge=""
-	if [ -f "$__git_repo_path/MERGE_HEAD" ]; then
+	if __git_pseudoref_exists MERGE_HEAD; then
 		merge="--merge"
 	fi
 	case "$cur" in