From 067f6e01f1a82041b6f9fa34e0de8149b211c64e Mon Sep 17 00:00:00 2001
From: gufe44 <56860520+gufe44@users.noreply.github.com>
Date: Thu, 30 Jul 2020 09:02:27 +0200
Subject: [PATCH] Fix bug in redirection of unit test outputs

Avoid replacing handle. stdout is defined as a macro on several platforms.

Signed-off-by: gufe44 <gu981@protonmail.com>
---
 ChangeLog.d/stdout-macro.txt    |  3 ++
 tests/suites/helpers.function   | 55 +++++++++++++++++++--------------
 tests/suites/host_test.function |  9 ++----
 3 files changed, 36 insertions(+), 31 deletions(-)
 create mode 100644 ChangeLog.d/stdout-macro.txt

diff --git a/ChangeLog.d/stdout-macro.txt b/ChangeLog.d/stdout-macro.txt
new file mode 100644
index 000000000..94562404a
--- /dev/null
+++ b/ChangeLog.d/stdout-macro.txt
@@ -0,0 +1,3 @@
+Bugfix
+   * Fix bug in redirection of unit test outputs on platforms where stdout is
+     defined as a macro. First reported in #2311 and fix contributed in #3528.
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index a5285a3a6..7425a359c 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -446,44 +446,51 @@ void mbedtls_param_failed( const char *failure_condition,
 #endif
 
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
-static int redirect_output( FILE** out_stream, const char* path )
+static int redirect_output( FILE* out_stream, const char* path )
 {
-    int stdout_fd = dup( fileno( *out_stream ) );
+    int out_fd, dup_fd;
+    FILE* path_stream;
 
-    if( stdout_fd == -1 )
+    out_fd = fileno( out_stream );
+    dup_fd = dup( out_fd );
+
+    if( dup_fd == -1 )
     {
-        return -1;
+        return( -1 );
     }
 
-    fflush( *out_stream );
-    fclose( *out_stream );
-    *out_stream = fopen( path, "w" );
-
-    if( *out_stream == NULL )
+    path_stream = fopen( path, "w" );
+    if( path_stream == NULL )
     {
-        close( stdout_fd );
-        return -1;
+        close( dup_fd );
+        return( -1 );
     }
 
-    return stdout_fd;
+    fflush( out_stream );
+    if( dup2( fileno( path_stream ), out_fd ) == -1 )
+    {
+        close( dup_fd );
+        fclose( path_stream );
+        return( -1 );
+    }
+
+    fclose( path_stream );
+    return( dup_fd );
 }
 
-static int restore_output( FILE** out_stream, int old_fd )
+static int restore_output( FILE* out_stream, int dup_fd )
 {
-    fflush( *out_stream );
-    fclose( *out_stream );
+    int out_fd = fileno( out_stream );
 
-    *out_stream = fdopen( old_fd, "w" );
-    if( *out_stream == NULL )
+    fflush( out_stream );
+    if( dup2( dup_fd, out_fd ) == -1 )
     {
-        return -1;
+        close( out_fd );
+        close( dup_fd );
+        return( -1 );
     }
 
-    return 0;
-}
-
-static void close_output( FILE* out_stream )
-{
-    fclose( out_stream );
+    close( dup_fd );
+    return( 0 );
 }
 #endif /* __unix__ || __APPLE__ __MACH__ */
diff --git a/tests/suites/host_test.function b/tests/suites/host_test.function
index a459eed56..cce2899f4 100644
--- a/tests/suites/host_test.function
+++ b/tests/suites/host_test.function
@@ -692,7 +692,7 @@ int execute_tests( int argc , const char ** argv )
                  */
                 if( !option_verbose )
                 {
-                    stdout_fd = redirect_output( &stdout, "/dev/null" );
+                    stdout_fd = redirect_output( stdout, "/dev/null" );
                     if( stdout_fd == -1 )
                     {
                         /* Redirection has failed with no stdout so exit */
@@ -712,7 +712,7 @@ int execute_tests( int argc , const char ** argv )
                 }
 
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
-                if( !option_verbose && restore_output( &stdout, stdout_fd ) )
+                if( !option_verbose && restore_output( stdout, stdout_fd ) )
                 {
                         /* Redirection has failed with no stdout so exit */
                         exit( 1 );
@@ -817,10 +817,5 @@ int execute_tests( int argc , const char ** argv )
     mbedtls_memory_buffer_alloc_free();
 #endif
 
-#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
-    if( stdout_fd != -1 )
-        close_output( stdout );
-#endif /* __unix__ || __APPLE__ __MACH__ */
-
     return( total_errors != 0 );
 }