[perl #30258] utf8 POPSTACK crash on split execution

split() does a SWITCHSTACK to directly split to an array, but
if it subsequently dies (eg the regex triggers a 'use utf8' which
is then denied by Safe), then the switch doesn't get undone. Add
a new save type to allow for this.

p4raw-id: //depot/perl@23023

1 files changed, 11 insertions, 0 deletions

diff --git a/scope.h b/scope.h
index bbb55628fe..f86039dbd1 100644
--- a/scope.h
+++ b/scope.h
@@ -48,6 +48,7 @@
 #define SAVEt_SHARED_PVREF	37
 #define SAVEt_BOOL		38
 #define SAVEt_SET_SVFLAGS	39
+#define SAVEt_SAVESWITCHSTACK	40
 
 #ifndef SCOPE_SAVES_SIGNAL_MASK
 #define SCOPE_SAVES_SIGNAL_MASK 0
@@ -169,6 +170,16 @@ Closing bracket on a callback.  See C<ENTER> and L<perlcall>.
 	SSPUSHINT(SAVEt_COMPPAD);				\
     } STMT_END
 
+#define SAVESWITCHSTACK(f,t) \
+    STMT_START {					\
+	SSCHECK(3);					\
+	SSPUSHPTR((SV*)(f));				\
+	SSPUSHPTR((SV*)(t));				\
+	SSPUSHINT(SAVEt_SAVESWITCHSTACK);		\
+	SWITCHSTACK((f),(t));				\
+	PL_curstackinfo->si_stack = (t);		\
+    } STMT_END
+
 #ifdef USE_ITHREADS
 #  define SAVECOPSTASH(c)	SAVEPPTR(CopSTASHPV(c))
 #  define SAVECOPSTASH_FREE(c)	SAVESHAREDPV(CopSTASHPV(c))