prognam: Add diagnostic.

[pspp] / lib / progname.c

diff --git a/lib/progname.c b/lib/progname.c
index c8660c94185dae61868f4cabb1a05ecdf97be1d1..2e82ac9ed6cc1b07b4eff0825452c8ae64213dcc 100644 (file)
--- a/lib/progname.c
+++ b/lib/progname.c
@@ -23,6 +23,8 @@
 #include "progname.h"
 
 #include <errno.h> /* get program_invocation_name declaration */
+#include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 
@@ -44,6 +46,16 @@ set_program_name (const char *argv0)
   const char *slash;
   const char *base;
 
+  /* Sanity check.  POSIX requires the invoking process to pass a non-NULL
+     argv[0].  */
+  if (argv0 == NULL)
+    {
+      /* It's a bug in the invoking program.  Help diagnosing it.  */
+      fputs ("A NULL argv[0] was passed through an exec system call.\n",
+            stderr);
+      abort ();
+    }
+
   slash = strrchr (argv0, '/');
   base = (slash != NULL ? slash + 1 : argv0);
   if (base - argv0 >= 7 && strncmp (base - 7, "/.libs/", 7) == 0)