t5411: use different out file to prevent overwriting

SZEDER reported that t5411 failed in Travis CI's s390x environment a
couple of times, and could be reproduced with '--stress' test on this
specific environment.  The test failure messages might look like this:

    + test_cmp expect actual
    --- expect      2021-01-17 21:55:23.430750004 +0000
    +++ actual      2021-01-17 21:55:23.430750004 +0000
    @@ -1 +1 @@
    -<COMMIT-A> refs/heads/main
    +<COMMIT-A> refs/heads/maifatal: the remote end hung up unexpectedly
    error: last command exited with $?=1
    not ok 86 - proc-receive: not support push options (builtin protocol)

The file 'actual' is filtered from the file 'out' which contains result
of 'git show-ref' command.  Due to the error messages from other process
is written into the file 'out' accidentally, t5411 failed.  SZEDER finds
the root cause of this issue:

 - 'git push' is executed with its standard output and error redirected
   to the file 'out'.

 - 'git push' executes 'git receive-pack' internally, which inherits
   the open file descriptors, so its output and error goes into that
   same 'out' file.

 - 'git push' ends without waiting for the close of 'git-receive-pack'
   for some cases, and the file 'out' is reused for test of
   'git show-ref' afterwards.

 - A mixture of the output of 'git show-ref' abd 'git receive-pack'
   leads to this issue.

The first intuitive reaction to resolve this issue is to remove the
file 'out' after use, so that the newly created file 'out' will have a
different file descriptor and will not be overwritten by the
'git receive-pack' process.  But Johannes pointed out that removing an
open file is not possible on Windows.  So we use different temporary
file names to store the output of 'git push' to solve this issue.

Reported-by: SZEDER Gábor <[email protected]>
Helped-by: Johannes Sixt <[email protected]>
Helped-by: SZEDER Gábor <[email protected]>
Signed-off-by: Jiang Xin <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jiangxin

t/t5411/test-0000-standard-git-push.sh

@@ -35,11 +35,11 @@ test_expect_success "git-push --atomic ($PROTOCOL)" '
 	test_must_fail git -C workbench push --atomic origin \
 		main \
 		$B:refs/heads/next \
-		>out 2>&1 &&
+		>out-$test_count 2>&1 &&
 	filter_out_user_friendly_and_stable_output \
 		-e "/^To / { p; }" \
 		-e "/^ ! / { p; }" \
-		<out >actual &&
+		<out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	 ! [rejected] main -> main (non-fast-forward)
@@ -65,8 +65,8 @@ test_expect_success "non-fast-forward git-push ($PROTOCOL)" '
 		push origin \
 		main \
 		$B:refs/heads/next \
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <COMMIT-A> <COMMIT-B> refs/heads/next

t/t5411/test-0001-standard-git-push--porcelain.sh

@@ -36,12 +36,12 @@ test_expect_success "git-push --atomic ($PROTOCOL/porcelain)" '
 	test_must_fail git -C workbench push --atomic --porcelain origin \
 		main \
 		$B:refs/heads/next \
-		>out 2>&1 &&
+		>out-$test_count 2>&1 &&
 	filter_out_user_friendly_and_stable_output \
 		-e "s/^# GETTEXT POISON #//" \
 		-e "/^To / { p; }" \
 		-e "/^! / { p; }" \
-		<out >actual &&
+		<out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	!    refs/heads/main:refs/heads/main    [rejected] (non-fast-forward)
@@ -67,8 +67,8 @@ test_expect_success "non-fast-forward git-push ($PROTOCOL/porcelain)" '
 		push --porcelain origin \
 		main \
 		$B:refs/heads/next \
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <COMMIT-A> <COMMIT-B> refs/heads/next

t/t5411/test-0002-pre-receive-declined.sh

@@ -12,8 +12,8 @@ test_expect_success "git-push is declined ($PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		$B:refs/heads/main \
 		HEAD:refs/heads/next \
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	 ! [remote rejected] <COMMIT-B> -> main (pre-receive hook declined)

t/t5411/test-0003-pre-receive-declined--porcelain.sh

@@ -12,8 +12,8 @@ test_expect_success "git-push is declined ($PROTOCOL/porcelain)" '
 	test_must_fail git -C workbench push --porcelain origin \
 		$B:refs/heads/main \
 		HEAD:refs/heads/next \
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	!    <COMMIT-B>:refs/heads/main    [remote rejected] (pre-receive hook declined)

t/t5411/test-0011-no-hook-error.sh

@@ -5,8 +5,8 @@ test_expect_success "proc-receive: no hook, fail to push special ref ($PROTOCOL)
 	test_must_fail git -C workbench push origin \
 		HEAD:next \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/next
@@ -41,8 +41,8 @@ test_expect_success "proc-receive: no hook, all failed for atomic push ($PROTOCO
 	test_must_fail git -C workbench push --atomic origin \
 		$B:main \
 		HEAD:next \
-		HEAD:refs/for/main/topic >out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		HEAD:refs/for/main/topic >out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <COMMIT-A> <COMMIT-B> refs/heads/main

t/t5411/test-0012-no-hook-error--porcelain.sh

@@ -5,8 +5,8 @@ test_expect_success "proc-receive: no hook, fail to push special ref ($PROTOCOL/
 	test_must_fail git -C workbench push --porcelain origin \
 		HEAD:next \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/next
@@ -42,8 +42,8 @@ test_expect_success "proc-receive: no hook, all failed for atomic push ($PROTOCO
 	test_must_fail git -C workbench push --porcelain --atomic origin \
 		$B:main \
 		HEAD:next \
-		HEAD:refs/for/main/topic >out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		HEAD:refs/for/main/topic >out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <COMMIT-A> <COMMIT-B> refs/heads/main

t/t5411/test-0013-bad-protocol.sh

@@ -11,8 +11,8 @@ test_expect_success "setup proc-receive hook (unknown version, $PROTOCOL)" '
 test_expect_success "proc-receive: bad protocol (unknown version, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 
 	# Check status report for git-push
 	sed -n \
@@ -55,18 +55,18 @@ test_expect_success "setup proc-receive hook (hook --die-read-version, $PROTOCOL
 test_expect_success "proc-receive: bad protocol (hook --die-read-version, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
+		>out-$test_count 2>&1 &&
 	filter_out_user_friendly_and_stable_output \
 		-e "/^To / { p; }" \
 		-e "/^ ! / { p; }" \
-		<out >actual &&
+		<out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	 ! [remote rejected] HEAD -> refs/for/main/topic (fail to run proc-receive hook)
 	EOF
 	test_cmp expect actual &&
-	grep "remote: fatal: die with the --die-read-version option" out &&
-	grep "remote: error: fail to negotiate version with proc-receive hook" out &&
+	grep "remote: fatal: die with the --die-read-version option" out-$test_count &&
+	grep "remote: error: fail to negotiate version with proc-receive hook" out-$test_count &&
 
 	git -C "$upstream" show-ref >out &&
 	make_user_friendly_and_stable_output <out >actual &&
@@ -89,18 +89,18 @@ test_expect_success "setup proc-receive hook (hook --die-write-version, $PROTOCO
 test_expect_success "proc-receive: bad protocol (hook --die-write-version, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
+		>out-$test_count 2>&1 &&
 	filter_out_user_friendly_and_stable_output \
 		-e "/^To / { p; }" \
 		-e "/^ ! / { p; }" \
-		<out >actual &&
+		<out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	 ! [remote rejected] HEAD -> refs/for/main/topic (fail to run proc-receive hook)
 	EOF
 	test_cmp expect actual &&
-	grep "remote: fatal: die with the --die-write-version option" out &&
-	grep "remote: error: fail to negotiate version with proc-receive hook" out &&
+	grep "remote: fatal: die with the --die-write-version option" out-$test_count &&
+	grep "remote: error: fail to negotiate version with proc-receive hook" out-$test_count &&
 
 	git -C "$upstream" show-ref >out &&
 	make_user_friendly_and_stable_output <out >actual &&
@@ -123,17 +123,17 @@ test_expect_success "setup proc-receive hook (hook --die-read-commands, $PROTOCO
 test_expect_success "proc-receive: bad protocol (hook --die-read-commands, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
+		>out-$test_count 2>&1 &&
 	filter_out_user_friendly_and_stable_output \
 		-e "/^To / { p; }" \
 		-e "/^ ! / { p; }" \
-		<out >actual &&
+		<out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	 ! [remote rejected] HEAD -> refs/for/main/topic (fail to run proc-receive hook)
 	EOF
 	test_cmp expect actual &&
-	grep "remote: fatal: die with the --die-read-commands option" out &&
+	grep "remote: fatal: die with the --die-read-commands option" out-$test_count &&
 
 	git -C "$upstream" show-ref >out &&
 	make_user_friendly_and_stable_output <out >actual &&
@@ -158,17 +158,17 @@ test_expect_success "proc-receive: bad protocol (hook --die-read-push-options, $
 	test_must_fail git -C workbench push origin \
 		-o reviewers=user1,user2 \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
+		>out-$test_count 2>&1 &&
 	filter_out_user_friendly_and_stable_output \
 		-e "/^To / { p; }" \
 		-e "/^ ! / { p; }" \
-		<out >actual &&
+		<out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	 ! [remote rejected] HEAD -> refs/for/main/topic (fail to run proc-receive hook)
 	EOF
 	test_cmp expect actual &&
-	grep "remote: fatal: die with the --die-read-push-options option" out &&
+	grep "remote: fatal: die with the --die-read-push-options option" out-$test_count &&
 
 	git -C "$upstream" show-ref >out &&
 	make_user_friendly_and_stable_output <out >actual &&
@@ -191,17 +191,17 @@ test_expect_success "setup proc-receive hook (hook --die-write-report, $PROTOCOL
 test_expect_success "proc-receive: bad protocol (hook --die-write-report, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		HEAD:refs/for/main/topic \
-		>out 2>&1 &&
+		>out-$test_count 2>&1 &&
 	filter_out_user_friendly_and_stable_output \
 		-e "/^To / { p; }" \
 		-e "/^ ! / { p; }" \
-		<out >actual &&
+		<out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	To <URL/of/upstream.git>
 	 ! [remote rejected] HEAD -> refs/for/main/topic (fail to run proc-receive hook)
 	EOF
 	test_cmp expect actual &&
-	grep "remote: fatal: die with the --die-write-report option" out &&
+	grep "remote: fatal: die with the --die-write-report option" out-$test_count &&
 
 	git -C "$upstream" show-ref >out &&
 	make_user_friendly_and_stable_output <out >actual &&
@@ -224,8 +224,8 @@ test_expect_success "setup proc-receive hook (no report, $PROTOCOL)" '
 test_expect_success "proc-receive: bad protocol (no report, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		HEAD:refs/heads/next \
-		HEAD:refs/for/main/topic >out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		HEAD:refs/for/main/topic >out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/heads/next
@@ -270,8 +270,8 @@ test_expect_success "setup proc-receive hook (no ref, $PROTOCOL)" '
 test_expect_success "proc-receive: bad protocol (no ref, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 		HEAD:refs/for/main/topic\
-		>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+		>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/main/topic
@@ -306,8 +306,8 @@ test_expect_success "setup proc-receive hook (unknown status, $PROTOCOL)" '
 test_expect_success "proc-receive: bad protocol (unknown status, $PROTOCOL)" '
 	test_must_fail git -C workbench push origin \
 			HEAD:refs/for/main/topic \
-			>out 2>&1 &&
-	make_user_friendly_and_stable_output <out >actual &&
+			>out-$test_count 2>&1 &&
+	make_user_friendly_and_stable_output <out-$test_count >actual &&
 	cat >expect <<-EOF &&
 	remote: # pre-receive hook
 	remote: pre-receive< <ZERO-OID> <COMMIT-A> refs/for/main/topic