regexec.c: Use get method instead of internals

A new get method has been written to access the internals of a swash
it's best to use it.

This also moves the error checking to the method

1 files changed, 7 insertions, 1 deletions

diff --git a/utf8.c b/utf8.c
index 6c43f8246e..b12d82c0ef 100644
--- a/utf8.c
+++ b/utf8.c
@@ -4142,10 +4142,16 @@ Perl__swash_to_invlist(pTHX_ SV* const swash)
 SV*
 Perl__get_swash_invlist(pTHX_ SV* const swash)
 {
-    SV** ptr = hv_fetchs(MUTABLE_HV(SvRV(swash)), "INVLIST", FALSE);
+    SV** ptr;
 
     PERL_ARGS_ASSERT__GET_SWASH_INVLIST;
 
+    if (! SvROK(swash) || SvTYPE(SvRV(swash)) != SVt_PVHV) {
+        return NULL;
+    }
+
+    ptr = hv_fetchs(MUTABLE_HV(SvRV(swash)), "INVLIST", FALSE);
+
     if (! ptr) {
         return NULL;
     }