btrfs-progs: tests: add helper to log pipe stdout

Signed-off-by: David Sterba <dsterba@suse.com>

tests/common

@@ -54,6 +54,13 @@ _log()
 	echo "$*" | tee -a "$RESULTS"
 }
 
+# copy stdout to log and pass to stdout, eg. another stdout consumer, commands
+# should redirect stderr to stdout if this is consmed by further commands
+_log_stdout()
+{
+	tee -a "$RESULTS"
+}
+
 _not_run()
 {
 	echo "    [NOTRUN] $*"

tests/misc-tests/029-send-p-different-mountpoints/test.sh

@@ -31,7 +31,7 @@ run_check $SUDO_HELPER "$TOP/btrfs" subvolume snapshot -r \
 run_mustfail_stdout "send -p on 2 mount points" \
 	$SUDO_HELPER "$TOP/btrfs" send -f /dev/null -p \
 	"$SUBVOL_MNT/test-subvol-mnt-subvol" "$TOPLEVEL_MNT/test-subvol-mnt-root" \
-	| tee -a "$RESULTS" \
+	| _log_stdout \
 	| grep -q "not on mount point.*/toplevel" \
 	|| _fail "expected output not found, please check the logs"