tests: add opipe.test

Check that -o |pipe_command works.  In particular, check that
strace waits for completion of piped command.

* tests/opipe.test: New test.
* tests/Makefile.am (TESTS): Add it.

tests/Makefile.am

@@ -311,6 +311,7 @@ TESTS = \
 	detach-sleeping.test \
 	detach-stopped.test \
 	detach-running.test \
+	opipe.test \
 	restart_syscall.test \
 	$(LIBUNWIND_TESTS)
 

tests/opipe.test

@@ -0,0 +1,19 @@
+#!/bin/sh
+
+# Check how -o '|pipe' works.
+
+. "${srcdir=.}/init.sh"
+
+OUT="$LOG.out"
+EXP="$LOG.exp"
+
+check_prog grep
+run_prog grep chdir $srcdir/umovestr.expected > "$EXP"
+run_prog ./umovestr
+
+> "$LOG" || fail_ "failed to write $LOG"
+$STRACE -o "|cat > $LOG && $SLEEP_A_BIT && grep chdir < $LOG > $OUT" -e chdir $args ||
+	dump_log_and_fail_with "$STRACE $args failed"
+
+match_diff "$OUT" "$EXP"
+rm -f "$EXP" "$OUT"