fix vos/vos.c to implement pow(0,0)

Message-Id: <200204242252.SAA07978@mailhub1.stratus.com>

p4raw-id: //depot/perl@16170

1 files changed, 21 insertions, 0 deletions

diff --git a/vos/vos.c b/vos/vos.c
index a72614c3f3..9876d705b4 100644
--- a/vos/vos.c
+++ b/vos/vos.c
@@ -2,6 +2,8 @@
 /* Written 02-01-02 by Nick Ing-Simmons (nick@ing-simmons.net) */
 /* Modified 02-03-27 by Paul Green (Paul.Green@stratus.com) to
      add socketpair() dummy. */
+/* Modified 02-04-24 by Paul Green (Paul.Green@stratus.com) to
+     have pow(0,0) return 1, avoiding c-1471. */
 /* End of modification history */
 
 #include <errno.h>
@@ -35,3 +37,22 @@ socketpair (int family, int type, int protocol, int fd[2]) {
  errno = ENOSYS;
  return -1;
 }
+
+/* Supply a private version of the power function that returns 1
+   for x**0.  This avoids c-1471.  Abigail's Japh tests depend
+   on this fix.  We leave all the other cases to the VOS C
+   runtime.  */
+
+double s_crt_pow(double *x, double *y);
+
+double pow(x,y)
+double x, y;
+{
+     if (y == 0e0)                 /* c-1471 */
+     {
+          errno = EDOM;
+          return (1e0);
+     }
+
+     return(s_crt_pow(&x,&y));
+}