submodule init: redirect stdout to stderr

Reroute the output of stdout to stderr as it is just informative
messages, not to be consumed by machines.

This should not regress any scripts that try to parse the
current output, as the output is already internationalized
and therefore unstable.

We want to init submodules from the helper for `submodule update`
in a later patch and the stdout output of said helper is consumed
by the parts of `submodule update` which are still written in shell.
So we have to be careful which messages are on stdout.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/submodule--helper.c

@@ -366,7 +366,8 @@ static void init_submodule(const char *path, const char *prefix, int quiet)
 			die(_("Failed to register url for submodule path '%s'"),
 			    displaypath);
 		if (!quiet)
-			printf(_("Submodule '%s' (%s) registered for path '%s'\n"),
+			fprintf(stderr,
+				_("Submodule '%s' (%s) registered for path '%s'\n"),
 				sub->name, url, displaypath);
 	}
 

t/t7406-submodule-update.sh

@@ -108,24 +108,36 @@ pwd=$(pwd)
 
 cat <<EOF >expect
 Submodule path '../super': checked out '$supersha1'
-Submodule 'merging' ($pwd/merging) registered for path '../super/merging'
-Submodule 'none' ($pwd/none) registered for path '../super/none'
-Submodule 'rebasing' ($pwd/rebasing) registered for path '../super/rebasing'
-Submodule 'submodule' ($pwd/submodule) registered for path '../super/submodule'
 Submodule path '../super/merging': checked out '$mergingsha1'
 Submodule path '../super/none': checked out '$nonesha1'
 Submodule path '../super/rebasing': checked out '$rebasingsha1'
 Submodule path '../super/submodule': checked out '$submodulesha1'
 EOF
 
+cat <<EOF >expect2
+Submodule 'merging' ($pwd/merging) registered for path '../super/merging'
+Submodule 'none' ($pwd/none) registered for path '../super/none'
+Submodule 'rebasing' ($pwd/rebasing) registered for path '../super/rebasing'
+Submodule 'submodule' ($pwd/submodule) registered for path '../super/submodule'
+Cloning into '$pwd/recursivesuper/super/merging'...
+done.
+Cloning into '$pwd/recursivesuper/super/none'...
+done.
+Cloning into '$pwd/recursivesuper/super/rebasing'...
+done.
+Cloning into '$pwd/recursivesuper/super/submodule'...
+done.
+EOF
+
 test_expect_success 'submodule update --init --recursive from subdirectory' '
 	git -C recursivesuper/super reset --hard HEAD^ &&
 	(cd recursivesuper &&
 	 mkdir tmp &&
 	 cd tmp &&
-	 git submodule update --init --recursive ../super >../../actual
+	 git submodule update --init --recursive ../super >../../actual 2>../../actual2
 	) &&
-	test_cmp expect actual
+	test_cmp expect actual &&
+	test_cmp expect2 actual2
 '
 
 apos="'";