NULL sv->sv_debug_file when freed

This field is used on DEBUG_LEAKING_SCALARS builds to track the file
where the SV was allocated. When freeing the SV, the string was
freed but the pointer was left pointing at the freed string.

So NULL it out.

1 files changed, 4 insertions, 1 deletions

diff --git a/sv.c b/sv.c
index a4290d92b3..5a7e319720 100644
--- a/sv.c
+++ b/sv.c
@@ -231,7 +231,10 @@ Public API:
 
 #ifdef DEBUG_LEAKING_SCALARS
 #  define FREE_SV_DEBUG_FILE(sv) STMT_START { \
-        if ((sv)->sv_debug_file) PerlMemShared_free((sv)->sv_debug_file); \
+        if ((sv)->sv_debug_file) {                   \
+            PerlMemShared_free((sv)->sv_debug_file); \
+            sv->sv_debug_file = NULL;                \
+        }                                            \
     } STMT_END
 #  define DEBUG_SV_SERIAL(sv)						    \
     DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%" UVxf ": (%05ld) del_SV\n",    \