execl, execlp memory leak

[Kevin Ryde]

        * posix.c (scm_execl, scm_execlp): Avoid memory leak under error throw.

This can be seen with for instance

        (while #t
          (false-if-exception
           (execl "nosuchprog")))

This would be for the 1.6 branch too.

--- posix.c.~1.125.~    2004-02-22 07:54:37.000000000 +1000
+++ posix.c     2004-02-24 19:37:00.000000000 +1000
@@ -909,9 +909,13 @@
 #define FUNC_NAME s_scm_execl
 {
   char **execargv;
+  int save_errno;
   SCM_VALIDATE_STRING (1, filename);
   execargv = allocate_string_pointers (args);
   execv (SCM_STRING_CHARS (filename), execargv);
+  save_errno = errno;
+  free (execargv);
+  errno = save_errno;
   SCM_SYSERROR;
   /* not reached.  */
   return SCM_BOOL_F;
@@ -929,9 +933,13 @@
 #define FUNC_NAME s_scm_execlp
 {
   char **execargv;
+  int save_errno;
   SCM_VALIDATE_STRING (1, filename);
   execargv = allocate_string_pointers (args);
   execvp (SCM_STRING_CHARS (filename), execargv);
+  save_errno = errno;
+  free (execargv);
+  errno = save_errno;
   SCM_SYSERROR;
   /* not reached.  */
   return SCM_BOOL_F;