Check additional return values in some test cases
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index 620c368..239f8a9 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -101,6 +101,7 @@
     mpi_init( &X );
 
     file = fopen( input_file, "r" );
+    TEST_ASSERT( file != NULL );
     TEST_ASSERT( mpi_read_file( &X, radix_X, file ) == result );
     fclose(file);
 
diff --git a/tests/suites/test_suite_pkwrite.function b/tests/suites/test_suite_pkwrite.function
index 455b9aa..2ea9409 100644
--- a/tests/suites/test_suite_pkwrite.function
+++ b/tests/suites/test_suite_pkwrite.function
@@ -17,6 +17,7 @@
     unsigned char check_buf[5000];
     int ret;
     FILE *f;
+    size_t ilen;
 
     memset( buf, 0, sizeof( buf ) );
     memset( check_buf, 0, sizeof( check_buf ) );
@@ -29,9 +30,10 @@
 
     f = fopen( key_file, "r" );
     TEST_ASSERT( f != NULL );
-    fread( check_buf, 1, sizeof( check_buf ) - 1, f );
+    ilen = fread( check_buf, 1, sizeof( check_buf ) - 1, f );
     fclose( f );
 
+    TEST_ASSERT( ilen == strlen( (char *) buf ) );
     TEST_ASSERT( strncmp( (char *) buf, (char *) check_buf, sizeof( buf ) ) == 0 );
 
     pk_free( &key );
@@ -46,6 +48,7 @@
     unsigned char check_buf[5000];
     int ret;
     FILE *f;
+    size_t ilen;
 
     memset( buf, 0, sizeof( buf ) );
     memset( check_buf, 0, sizeof( check_buf ) );
@@ -58,9 +61,10 @@
 
     f = fopen( key_file, "r" );
     TEST_ASSERT( f != NULL );
-    fread( check_buf, 1, sizeof( check_buf ) - 1, f );
+    ilen = fread( check_buf, 1, sizeof( check_buf ) - 1, f );
     fclose( f );
 
+    TEST_ASSERT( ilen == strlen( (char *) buf ) );
     TEST_ASSERT( strncmp( (char *) buf, (char *) check_buf, sizeof( buf ) ) == 0 );
 
     pk_free( &key );