SF bug 595919: popenN return only text mode pipes

popen2() and popen3() created text-mode pipes even when binary mode
was asked for.  This was specific to Windows.

Modules/posixmodule.c

@@ -3476,7 +3476,7 @@ _PyPopen(char *cmdstring, int mode, int n)
 		 char *m1, *m2;
 		 PyObject *p1, *p2;
 
-		 if (mode && _O_TEXT) {
+		 if (mode & _O_TEXT) {
 			 m1 = "r";
 			 m2 = "w";
 		 } else {
@@ -3508,7 +3508,7 @@ _PyPopen(char *cmdstring, int mode, int n)
 		 char *m1, *m2;
 		 PyObject *p1, *p2, *p3;
 
-		 if (mode && _O_TEXT) {
+		 if (mode & _O_TEXT) {
 			 m1 = "r";
 			 m2 = "w";
 		 } else {