mg.c uses a fixed NGROUPS contant

# New Ticket Created by  casper.dik@sun.com
# Please include the string:  [perl #69977]
# in the subject line of all future correspondence about this issue.
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=69977 >

This is a bug report for perl from casper.dik@sun.com,
generated with the help of perlbug 1.36 running under perl 5.10.0.

-----------------------------------------------------------------
[Please enter your report here]

In mg.c NGROUPS is defined as follows:

#if defined(HAS_SETGROUPS)
#  ifndef NGROUPS
#    define NGROUPS 32
#  endif
#endif

and uses it later here:

  2632  #ifdef HAS_SETGROUPS
  2633          {
  2634              const char *p = SvPV_const(sv, len);
  2635              Groups_t *gary = NULL;
  2636
  2637              while (isSPACE(*p))
  2638                  ++p;
  2639              PL_egid = Atol(p);
  2640              for (i = 0; i < NGROUPS; ++i) {
  2641                  while (*p && !isSPACE(*p))
  2642                      ++p;
  2643                  while (isSPACE(*p))
  2644                      ++p;
  2645                  if (!*p)
  2646                      break;
  2647                  if(!gary)
  2648                      Newx(gary, i + 1, Groups_t);
  2649                  else
  2650                      Renew(gary, i + 1, Groups_t);
  2651                  gary[i] = Atol(p);
  2652              }
  2653              if (i)
  2654                  (void)setgroups(i, gary);
  2655              Safefree(gary);
  2656          }
  2657  #else  /* HAS_SETGROUPS */

This should be changed as follows

1 files changed, 9 insertions, 1 deletions

diff --git a/mg.c b/mg.c
index 05f8cd97cb..aaed62d696 100644
--- a/mg.c
+++ b/mg.c
@@ -2667,11 +2667,19 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	{
 	    const char *p = SvPV_const(sv, len);
             Groups_t *gary = NULL;
+#ifdef _SC_NGROUPS_MAX
+           int maxgrp = sysconf(_SC_NGROUPS_MAX);
+
+           if (maxgrp < 0)
+               maxgrp = NGROUPS;
+#else
+           int maxgrp = NGROUPS;
+#endif
 
             while (isSPACE(*p))
                 ++p;
             PL_egid = Atol(p);
-            for (i = 0; i < NGROUPS; ++i) {
+            for (i = 0; i < maxgrp; ++i) {
                 while (*p && !isSPACE(*p))
                     ++p;
                 while (isSPACE(*p))