completion: rename internal helpers _git and _gitk

Would be useful to provide backwards compatibility for _git. Also, zsh
completion uses _git, and it cannot be changed.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -2599,7 +2599,7 @@ _git_whatchanged ()
 	_git_log
 }
 
-_git ()
+_main_git ()
 {
 	local i c=1 command __git_dir
 
@@ -2650,7 +2650,7 @@ _git ()
 	fi
 }
 
-_gitk ()
+_main_gitk ()
 {
 	__git_has_doubledash && return
 
@@ -2702,13 +2702,13 @@ __git_complete ()
 		|| complete -o default -o nospace -F $wrapper $1
 }
 
-__git_complete git _git
-__git_complete gitk _gitk
+__git_complete git _main_git
+__git_complete gitk _main_gitk
 
 # The following are necessary only for Cygwin, and only are needed
 # when the user has tab-completed the executable name and consequently
 # included the '.exe' suffix.
 #
 if [ Cygwin = "$(uname -o 2>/dev/null)" ]; then
-__git_complete git.exe _git
+__git_complete git.exe _main_git
 fi

t/t9902-completion.sh

@@ -63,7 +63,7 @@ run_completion ()
 	local _cword
 	_words=( $1 )
 	(( _cword = ${#_words[@]} - 1 ))
-	__git_wrap_git && print_comp
+	__git_wrap_main_git && print_comp
 }
 
 test_completion ()