git-completion.bash: use $__git_cmd_idx in more places

With the introduction of the $__git_cmd_idx variable in e94fb44042
(git-completion.bash: pass $__git_subcommand_idx from __git_main(),
2021-03-24), completion functions were able to know the index at which
the git command is listed, allowing them to skip options that are given
to the underlying git itself, not the corresponding command (e.g.
`-C asdf` in `git -C asdf branch`).

While most of the changes here are self-explanatory, some bear further
explanation.

For the __git_find_on_cmdline() and __git_find_last_on_cmdline() pair of
functions, these functions are only ever called in the context of a git
command completion function. These functions will only care about words
after the command so we can safely ignore the words before this.

For _git_worktree(), this change is technically a no-op (once the
__git_find_last_on_cmdline change is also applied). It was in poor style
to have hard-coded on the index right after `worktree`. In case
`git worktree` were to ever learn to accept options, the current
situation would be inflexible.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -1006,8 +1006,8 @@ __git_complete_revlist ()
 
 __git_complete_remote_or_refspec ()
 {
-	local cur_="$cur" cmd="${words[1]}"
-	local i c=2 remote="" pfx="" lhs=1 no_complete_refspec=0
+	local cur_="$cur" cmd="${words[__git_cmd_idx]}"
+	local i c=$((__git_cmd_idx+1)) remote="" pfx="" lhs=1 no_complete_refspec=0
 	if [ "$cmd" = "remote" ]; then
 		((c++))
 	fi
@@ -1176,7 +1176,7 @@ __git_aliased_command ()
 # --show-idx: Optionally show the index of the found word in the $words array.
 __git_find_on_cmdline ()
 {
-	local word c=1 show_idx
+	local word c="$__git_cmd_idx" show_idx
 
 	while test $# -gt 1; do
 		case "$1" in
@@ -1221,7 +1221,7 @@ __git_find_last_on_cmdline ()
 	done
 	local wordlist="$1"
 
-	while [ $c -gt 1 ]; do
+	while [ $c -gt "$__git_cmd_idx" ]; do
 		((c--))
 		for word in $wordlist; do
 			if [ "$word" = "${words[c]}" ]; then
@@ -1306,7 +1306,7 @@ __git_count_arguments ()
 	local word i c=0
 
 	# Skip "git" (first argument)
-	for ((i=1; i < ${#words[@]}; i++)); do
+	for ((i="$__git_cmd_idx"; i < ${#words[@]}; i++)); do
 		word="${words[i]}"
 
 		case "$word" in
@@ -1442,7 +1442,7 @@ __git_ref_fieldlist="refname objecttype objectsize objectname upstream push HEAD
 
 _git_branch ()
 {
-	local i c=1 only_local_ref="n" has_r="n"
+	local i c="$__git_cmd_idx" only_local_ref="n" has_r="n"
 
 	while [ $c -lt $cword ]; do
 		i="${words[c]}"
@@ -2474,7 +2474,7 @@ _git_switch ()
 __git_config_get_set_variables ()
 {
 	local prevword word config_file= c=$cword
-	while [ $c -gt 1 ]; do
+	while [ $c -gt "$__git_cmd_idx" ]; do
 		word="${words[c]}"
 		case "$word" in
 		--system|--global|--local|--file=*)
@@ -3224,7 +3224,7 @@ _git_svn ()
 
 _git_tag ()
 {
-	local i c=1 f=0
+	local i c="$__git_cmd_idx" f=0
 	while [ $c -lt $cword ]; do
 		i="${words[c]}"
 		case "$i" in
@@ -3276,9 +3276,11 @@ __git_complete_worktree_paths ()
 _git_worktree ()
 {
 	local subcommands="add list lock move prune remove unlock"
-	local subcommand
+	local subcommand subcommand_idx
 
-	subcommand="$(__git_find_on_cmdline "$subcommands")"
+	subcommand="$(__git_find_on_cmdline --show-idx "$subcommands")"
+	subcommand_idx="${subcommand% *}"
+	subcommand="${subcommand#* }"
 
 	case "$subcommand,$cur" in
 	,*)
@@ -3303,7 +3305,7 @@ _git_worktree ()
 			# be either the 'add' subcommand, the unstuck
 			# argument of an option (e.g. branch for -b|-B), or
 			# the path for the new worktree.
-			if [ $cword -eq $((__git_cmd_idx+2)) ]; then
+			if [ $cword -eq $((subcommand_idx+1)) ]; then
 				# Right after the 'add' subcommand: have to
 				# complete the path, so fall back to Bash
 				# filename completion.
@@ -3327,7 +3329,7 @@ _git_worktree ()
 		__git_complete_worktree_paths
 		;;
 	move,*)
-		if [ $cword -eq $((__git_cmd_idx+2)) ]; then
+		if [ $cword -eq $((subcommand_idx+1)) ]; then
 			# The first parameter must be an existing working
 			# tree to be moved.
 			__git_complete_worktree_paths

t/t9902-completion.sh

@@ -1879,6 +1879,7 @@ test_expect_success '__git_find_on_cmdline - single match' '
 	(
 		words=(git command --opt list) &&
 		cword=${#words[@]} &&
+		__git_cmd_idx=1 &&
 		__git_find_on_cmdline "add list remove" >actual
 	) &&
 	test_cmp expect actual
@@ -1889,6 +1890,7 @@ test_expect_success '__git_find_on_cmdline - multiple matches' '
 	(
 		words=(git command -o --opt remove list add) &&
 		cword=${#words[@]} &&
+		__git_cmd_idx=1 &&
 		__git_find_on_cmdline "add list remove" >actual
 	) &&
 	test_cmp expect actual
@@ -1898,6 +1900,7 @@ test_expect_success '__git_find_on_cmdline - no match' '
 	(
 		words=(git command --opt branch) &&
 		cword=${#words[@]} &&
+		__git_cmd_idx=1 &&
 		__git_find_on_cmdline "add list remove" >actual
 	) &&
 	test_must_be_empty actual
@@ -1908,6 +1911,7 @@ test_expect_success '__git_find_on_cmdline - single match with index' '
 	(
 		words=(git command --opt list) &&
 		cword=${#words[@]} &&
+		__git_cmd_idx=1 &&
 		__git_find_on_cmdline --show-idx "add list remove" >actual
 	) &&
 	test_cmp expect actual
@@ -1918,6 +1922,7 @@ test_expect_success '__git_find_on_cmdline - multiple matches with index' '
 	(
 		words=(git command -o --opt remove list add) &&
 		cword=${#words[@]} &&
+		__git_cmd_idx=1 &&
 		__git_find_on_cmdline --show-idx "add list remove" >actual
 	) &&
 	test_cmp expect actual
@@ -1927,11 +1932,23 @@ test_expect_success '__git_find_on_cmdline - no match with index' '
 	(
 		words=(git command --opt branch) &&
 		cword=${#words[@]} &&
+		__git_cmd_idx=1 &&
 		__git_find_on_cmdline --show-idx "add list remove" >actual
 	) &&
 	test_must_be_empty actual
 '
 
+test_expect_success '__git_find_on_cmdline - ignores matches before command with index' '
+	echo "6 remove" >expect &&
+	(
+		words=(git -C remove command -o --opt remove list add) &&
+		cword=${#words[@]} &&
+		__git_cmd_idx=3 &&
+		__git_find_on_cmdline --show-idx "add list remove" >actual
+	) &&
+	test_cmp expect actual
+'
+
 test_expect_success '__git_get_config_variables' '
 	cat >expect <<-EOF &&
 	name-1
@@ -2275,6 +2292,7 @@ do
 		(
 			words=(git push '$flag' other ma) &&
 			cword=${#words[@]} cur=${words[cword-1]} &&
+			__git_cmd_idx=1 &&
 			__git_complete_remote_or_refspec &&
 			print_comp
 		) &&
@@ -2288,6 +2306,7 @@ do
 		(
 			words=(git push other '$flag' ma) &&
 			cword=${#words[@]} cur=${words[cword-1]} &&
+			__git_cmd_idx=1 &&
 			__git_complete_remote_or_refspec &&
 			print_comp
 		) &&