Make atan2(0,0) return undef

p4raw-id: //depot/perl@33676

1 files changed, 4 insertions, 1 deletions

diff --git a/pp.c b/pp.c
index d940d104c1..145e74cd15 100644
--- a/pp.c
+++ b/pp.c
@@ -2798,7 +2798,10 @@ PP(pp_atan2)
     dVAR; dSP; dTARGET; tryAMAGICbin(atan2,0);
     {
       dPOPTOPnnrl;
-      SETn(Perl_atan2(left, right));
+      if (left == 0.0 && right == 0.0)
+	  SETs(&PL_sv_undef);
+      else
+	  SETn(Perl_atan2(left, right));
       RETURN;
     }
 }