Merge branch 'nd/parseopt-completion-more'

The mechanism to use parse-options API to automate the command line
completion continues to get extended and polished.

* nd/parseopt-completion-more:
  completion: use __gitcomp_builtin in _git_cherry
  completion: use __gitcomp_builtin in _git_ls_tree
  completion: delete option-only completion commands
  completion: add --option completion for most builtin commands
  completion: factor out _git_xxx calling code
  completion: mention the oldest version we need to support
  git.c: add hidden option --list-parseopt-builtins
  git.c: move cmd_struct declaration up

contrib/completion/git-completion.bash

@@ -29,6 +29,8 @@
 # tell the completion to use commit completion.  This also works with aliases
 # of form "!sh -c '...'".  For example, "!sh -c ': git commit ; ... '".
 #
+# Compatible with bash 3.2.57.
+#
 # You can set the following environment variables to influence the behavior of
 # the completion routines:
 #
@@ -1284,6 +1286,12 @@ _git_checkout ()
 
 _git_cherry ()
 {
+	case "$cur" in
+	--*)
+		__gitcomp_builtin cherry
+		return
+	esac
+
 	__git_complete_refs
 }
 
@@ -1503,16 +1511,6 @@ _git_fsck ()
 	esac
 }
 
-_git_gc ()
-{
-	case "$cur" in
-	--*)
-		__gitcomp_builtin gc
-		return
-		;;
-	esac
-}
-
 _git_gitk ()
 {
 	_gitk
@@ -1637,6 +1635,13 @@ _git_ls_remote ()
 
 _git_ls_tree ()
 {
+	case "$cur" in
+	--*)
+		__gitcomp_builtin ls-tree
+		return
+		;;
+	esac
+
 	__git_complete_file
 }
 
@@ -1812,11 +1817,6 @@ _git_mv ()
 	fi
 }
 
-_git_name_rev ()
-{
-	__gitcomp_builtin name-rev
-}
-
 _git_notes ()
 {
 	local subcommands='add append copy edit get-ref list merge prune remove show'
@@ -3036,6 +3036,45 @@ _git_worktree ()
 	fi
 }
 
+__git_complete_common () {
+	local command="$1"
+
+	case "$cur" in
+	--*)
+		__gitcomp_builtin "$command"
+		;;
+	esac
+}
+
+__git_cmds_with_parseopt_helper=
+__git_support_parseopt_helper () {
+	test -n "$__git_cmds_with_parseopt_helper" ||
+		__git_cmds_with_parseopt_helper="$(__git --list-parseopt-builtins)"
+
+	case " $__git_cmds_with_parseopt_helper " in
+	*" $1 "*)
+		return 0
+		;;
+	*)
+		return 1
+		;;
+	esac
+}
+
+__git_complete_command () {
+	local command="$1"
+	local completion_func="_git_${command//-/_}"
+	if declare -f $completion_func >/dev/null 2>/dev/null; then
+		$completion_func
+		return 0
+	elif __git_support_parseopt_helper "$command"; then
+		__git_complete_common "$command"
+		return 0
+	else
+		return 1
+	fi
+}
+
 __git_main ()
 {
 	local i c=1 command __git_dir __git_repo_path
@@ -3095,14 +3134,12 @@ __git_main ()
 		return
 	fi
 
-	local completion_func="_git_${command//-/_}"
-	declare -f $completion_func >/dev/null 2>/dev/null && $completion_func && return
+	__git_complete_command "$command" && return
 
 	local expansion=$(__git_aliased_command "$command")
 	if [ -n "$expansion" ]; then
 		words[1]=$expansion
-		completion_func="_git_${expansion//-/_}"
-		declare -f $completion_func >/dev/null 2>/dev/null && $completion_func
+		__git_complete_command "$expansion"
 	fi
 }