completion: Replace config --list with --get-regexp

James Bardin noted that the completion spewed warnings when no git config
file is present.  This is likely a bug to be fixed in git config, but it's
also good to simplify the completion code by using the --get-regexp option
as Jeff King pointed out.

Signed-off-by: Todd Zullinger <tmz@pobox.com>
Trivially-acked-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -318,13 +318,9 @@ __git_remotes ()
 		echo ${i#$d/remotes/}
 	done
 	[ "$ngoff" ] && shopt -u nullglob
-	for i in $(git --git-dir="$d" config --list); do
-		case "$i" in
-		remote.*.url=*)
-			i="${i#remote.}"
-			echo "${i/.url=*/}"
-			;;
-		esac
+	for i in $(git --git-dir="$d" config --get-regexp 'remote\..*\.url' 2>/dev/null); do
+		i="${i#remote.}"
+		echo "${i/.url*/}"
 	done
 }
 
@@ -605,13 +601,9 @@ __git_porcelain_commandlist="$(__git_porcelain_commands 2>/dev/null)"
 __git_aliases ()
 {
 	local i IFS=$'\n'
-	for i in $(git --git-dir="$(__gitdir)" config --list); do
-		case "$i" in
-		alias.*)
-			i="${i#alias.}"
-			echo "${i/=*/}"
-			;;
-		esac
+	for i in $(git --git-dir="$(__gitdir)" config --get-regexp "alias\..*" 2>/dev/null); do
+		i="${i#alias.}"
+		echo "${i/ */}"
 	done
 }
 
@@ -1769,13 +1761,9 @@ _git_remote ()
 		;;
 	update)
 		local i c='' IFS=$'\n'
-		for i in $(git --git-dir="$(__gitdir)" config --list); do
-			case "$i" in
-			remotes.*)
-				i="${i#remotes.}"
-				c="$c ${i/=*/}"
-				;;
-			esac
+		for i in $(git --git-dir="$(__gitdir)" config --get-regexp "remotes\..*" 2>/dev/null); do
+			i="${i#remotes.}"
+			c="$c ${i/ */}"
 		done
 		__gitcomp "$c"
 		;;