Integrate change #11051 from macperl; O_RDONLY is not zero

everywhere.

p4raw-link: @11051 on //depot/perl: 497b47a829dd93323de2c7f4f6815ab9f23d6ada

p4raw-id: //depot/perl@11503
p4raw-integrated: from //depot/maint-5.6/macperl@11502 'merge in'
	doio.c (@11007..)

1 files changed, 1 insertions, 1 deletions

diff --git a/doio.c b/doio.c
index e8ee679f52..a20d4e2fd0 100644
--- a/doio.c
+++ b/doio.c
@@ -174,7 +174,7 @@ Perl_do_openn(pTHX_ GV *gv, register char *name, I32 len, int as_raw,
 	     IoTYPE(io) = IoTYPE_RDWR;
 	     break;
 	}
-	writing = (result > 0);
+	writing = (result != O_RDONLY);
 
 	if (result == O_RDONLY) {
 	    mode[ix++] = 'r';