Fix bug in mpi_safe_cond_assign()
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index ee9b94a..394cd33 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -309,13 +309,16 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
-void mpi_safe_cond_assign( char *x_str, char *y_str )
+void mpi_safe_cond_assign( int x_sign, char *x_str,
+                           int y_sign, char *y_str )
 {
     mpi X, Y, XX;
     mpi_init( &X ); mpi_init( &Y ); mpi_init( &XX );
 
     TEST_ASSERT( mpi_read_string( &X, 16, x_str ) == 0 );
+    X.s = x_sign;
     TEST_ASSERT( mpi_read_string( &Y, 16, y_str ) == 0 );
+    Y.s = y_sign;
     TEST_ASSERT( mpi_copy( &XX, &X ) == 0 );
 
     TEST_ASSERT( mpi_safe_cond_assign( &X, &Y, 0 ) == 0 );