From 03aa3467f35715b6449aca339cf96209ef579a6c Mon Sep 17 00:00:00 2001
From: arvidn <arvid@cs.umu.se>
Date: Sat, 31 Dec 2016 01:11:27 -0500
Subject: [PATCH] don't redirect stderr by default in unit tests (in case the
 sanitizers fire and print stuff)

---
 test/main.cpp | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/test/main.cpp b/test/main.cpp
index 2c0310895..9ef68de4f 100644
--- a/test/main.cpp
+++ b/test/main.cpp
@@ -71,7 +71,7 @@ using namespace libtorrent;
 int old_stdout = -1;
 int old_stderr = -1;
 bool redirect_stdout = true;
-bool redirect_stderr = true;
+bool redirect_stderr = false;
 bool keep_files = false;
 
 extern int _g_test_idx;
@@ -81,8 +81,10 @@ unit_test_t* current_test = nullptr;
 
 void output_test_log_to_terminal()
 {
-	if (current_test == nullptr || old_stdout == -1 || old_stderr == -1
-		|| !redirect_stdout || current_test->output == nullptr)
+	if (current_test == nullptr
+		|| (old_stdout == -1 && old_stderr == -1)
+		|| (!redirect_stdout && !redirect_stderr)
+		|| current_test->output == nullptr)
 		return;
 
 	fflush(stdout);
@@ -209,10 +211,7 @@ void print_usage(char const* executable)
 		"-n,--no-redirect     don't redirect test output to\n"
 		"                     temporary file, but let it go straight\n"
 		"                     to stdout\n"
-		"--no-stderr-redirect don't redirect stderr, but still redirect\n"
-		"                     stdout. This is useful when building with\n"
-		"                     sanitizers, which rely on being able to print\n"
-		"                     to stderr and exit\n"
+		"--stderr-redirect    also redirect stderr in addition to stdout\n"
 		"\n"
 		"for tests, specify one or more test names as printed\n"
 		"by -l. If no test is specified, all tests are run\n", executable);
@@ -247,12 +246,11 @@ EXPORT int main(int argc, char const* argv[])
 		if (strcmp(argv[0], "-n") == 0 || strcmp(argv[0], "--no-redirect") == 0)
 		{
 			redirect_stdout = false;
-			redirect_stderr = false;
 		}
 
-		if (strcmp(argv[0], "--no-stderr-redirect") == 0)
+		if (strcmp(argv[0], "--stderr-redirect") == 0)
 		{
-			redirect_stderr = false;
+			redirect_stderr = true;
 		}
 
 		if (strcmp(argv[0], "-k") == 0 || strcmp(argv[0], "--keep") == 0)
@@ -361,7 +359,7 @@ EXPORT int main(int argc, char const* argv[])
 
 		unit_test_t& t = _g_unit_tests[i];
 
-		if (redirect_stdout)
+		if (redirect_stdout || redirect_stderr)
 		{
 			// redirect test output to a temporary file
 			fflush(stdout);
@@ -370,8 +368,9 @@ EXPORT int main(int argc, char const* argv[])
 			FILE* f = tmpfile();
 			if (f != nullptr)
 			{
-				int ret1 = dup2(fileno(f), fileno(stdout));
-				if (redirect_stderr) dup2(fileno(f), fileno(stderr));
+				int ret1 = 0;
+				if (redirect_stdout) ret1 |= dup2(fileno(f), fileno(stdout));
+				if (redirect_stderr) ret1 |= dup2(fileno(f), fileno(stderr));
 				if (ret1 >= 0)
 				{
 					t.output = f;