fix coredump under usethreads+debug

p4raw-id: //depot/perl@3876

1 files changed, 1 insertions, 0 deletions

diff --git a/util.c b/util.c
index 1892c27103..762be7bb33 100644
--- a/util.c
+++ b/util.c
@@ -3407,6 +3407,7 @@ Perl_new_struct_thread(pTHX_ struct perl_thread *t)
     PL_screamnext = 0;
     PL_reg_start_tmp = 0;
     PL_reg_start_tmpl = 0;
+    PL_reg_poscache = Nullch;
 
     /* parent thread's data needs to be locked while we make copy */
     MUTEX_LOCK(&t->mutex);