Patch to fix segfaults in join-thread

[satchell]

In guile 1.4, join-thread segfaults when joining a dead thread. 

The following patch fixes this, it is diff -u against coop.c in libguile
--- coop.c~     Mon Jun 12 13:43:35 2000
+++ coop.c      Wed Sep  6 09:15:10 2000
@@ -722,8 +722,11 @@
   coop_t *old, *newthread;
   
   /* Check if t is already finished */
+  if (t == NULL)
+    return;
   if (t->base == NULL)
     return;


   /* Create a join list if necessary */
   if (t->joining == NULL)
[
To see the problem try the following
(let ((a (begin-thread (+ 1 1))))
(sleep 1)
(join-thread a)
)

julian satchell
<address@hidden>