Merge branch 'fc/transport-helper-error-reporting'

Update transport helper to report errors and maintain ref hierarchy
used to keep track of remote helper state better.

* fc/transport-helper-error-reporting:
  transport-helper: fix remote helper namespace regression
  test: remote-helper: add missing and
  t5801: "VAR=VAL shell_func args" is forbidden
  transport-helper: update remote helper namespace
  transport-helper: trivial code shuffle
  transport-helper: warn when refspec is not used
  transport-helper: clarify pushing without refspecs
  transport-helper: update refspec documentation
  transport-helper: clarify *:* refspec
  transport-helper: improve push messages
  transport-helper: mention helper name when it dies
  transport-helper: report errors properly

git-remote-testgit

@@ -62,12 +62,31 @@ do
 			echo "feature import-marks=$gitmarks"
 			echo "feature export-marks=$gitmarks"
 		fi
+
+		if test -n "$GIT_REMOTE_TESTGIT_FAILURE"
+		then
+			echo "feature done"
+			exit 1
+		fi
+
 		echo "feature done"
 		git fast-export "${testgitmarks_args[@]}" $refs |
 		sed -e "s#refs/heads/#${prefix}/heads/#g"
 		echo "done"
 		;;
 	export)
+		if test -n "$GIT_REMOTE_TESTGIT_FAILURE"
+		then
+			# consume input so fast-export doesn't get SIGPIPE;
+			# git would also notice that case, but we want
+			# to make sure we are exercising the later
+			# error checks
+			while read line; do
+				test "done" = "$line" && break
+			done
+			exit 1
+		fi
+
 		before=$(git for-each-ref --format='%(refname) %(objectname)')
 
 		git fast-import "${testgitmarks_args[@]}" --quiet
@@ -79,7 +98,12 @@ do
 		while read ref a b
 		do
 			test $a == $b && continue
-			echo "ok $ref"
+			if test -z "$GIT_REMOTE_TESTGIT_PUSH_ERROR"
+			then
+				echo "ok $ref"
+			else
+				echo "error $ref $GIT_REMOTE_TESTGIT_PUSH_ERROR"
+			fi
 		done
 
 		echo