Ensure PL_comppad/curpad point to PL_main_cv's padlist when

PL_main_root is freed; this may not have been be the case if a
thread other than the main one is the last to be destroyed

p4raw-id: //depot/perl@21470

3 files changed, 19 insertions, 3 deletions

diff --git a/ext/threads/t/thread.t b/ext/threads/t/thread.t
index c58ce00a99..2935fc2517 100644
--- a/ext/threads/t/thread.t
+++ b/ext/threads/t/thread.t
@@ -12,7 +12,7 @@ BEGIN {
 
 use ExtUtils::testlib;
 use strict;
-BEGIN { $| = 1; print "1..25\n" };
+BEGIN { $| = 1; print "1..26\n" };
 use threads;
 use threads::shared;
 
@@ -153,5 +153,10 @@ package main;
     ok((keys %rand == 25), "Check that rand works after a new thread");
 }
 
+# bugid #24165
+
+run_perl(prog =>
+    'use threads; sub a{threads->new(shift)} $t = a sub{}; $t->tid; $t->join; $t->tid');
+is($?, 0, 'coredump in global destruction');
 
 
diff --git a/pad.h b/pad.h
index cc31777912..e839042722 100644
--- a/pad.h
+++ b/pad.h
@@ -105,6 +105,9 @@ Get the value from slot C<po> in the base (DEPTH=1) pad of a padlist
 Set the current pad to be pad C<n> in the padlist, saving
 the previous current pad.
 
+=for apidoc m|void|PAD_SET_CUR_NOSAVE	|PADLIST padlist|I32 n
+like PAD_SET_CUR, but without the save
+
 =for apidoc m|void|PAD_SAVE_SETNULLPAD
 Save the current pad then set it to null.
 
@@ -133,8 +136,7 @@ Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL()
 	    ? AvARRAY((AV*)(AvARRAY(padlist)[1]))[po] : Nullsv;
     
 
-#define PAD_SET_CUR(padlist,n) \
-	SAVECOMPPAD();						\
+#define PAD_SET_CUR_NOSAVE(padlist,n) \
 	PL_comppad = (PAD*) (AvARRAY(padlist)[n]);		\
 	PL_curpad = AvARRAY(PL_comppad);			\
 	DEBUG_Xv(PerlIO_printf(Perl_debug_log,			\
@@ -142,6 +144,11 @@ Restore the old pad saved into the local variable opad by PAD_SAVE_LOCAL()
 	      PTR2UV(PL_comppad), PTR2UV(PL_curpad), (int)(n)));
 
 
+#define PAD_SET_CUR(padlist,n) \
+	SAVECOMPPAD();						\
+	PAD_SET_CUR_NOSAVE(padlist,n);
+
+
 #define PAD_SAVE_SETNULLPAD()	SAVECOMPPAD(); \
 	PL_comppad = Null(PAD*); PL_curpad = Null(SV**);	\
 	DEBUG_Xv(PerlIO_printf(Perl_debug_log, "Pad set_null\n"));
diff --git a/perl.c b/perl.c
index c707900a54..889b49326e 100644
--- a/perl.c
+++ b/perl.c
@@ -354,6 +354,10 @@ perl_destruct(pTHXx)
 
     /* Destroy the main CV and syntax tree */
     if (PL_main_root) {
+	/* ensure comppad/curpad to refer to main's pad */
+	if (CvPADLIST(PL_main_cv)) {
+	    PAD_SET_CUR_NOSAVE(CvPADLIST(PL_main_cv), 1);
+	}
 	op_free(PL_main_root);
 	PL_main_root = Nullop;
     }