[perl #45147] Issue with the exists function

Perl_av_exists tested to see if regdata magic was present,
but did not have any logic to fetch that data in the positive
key case.  Additionally, in the negative key case, if AvFILL
indicated the key existed, it wouldn't return, and would then
fall through to the logic that treated it like a real array.

1 files changed, 12 insertions, 1 deletions

diff --git a/av.c b/av.c
index d6db6bf195..8408220aff 100644
--- a/av.c
+++ b/av.c
@@ -901,7 +901,9 @@ Perl_av_exists(pTHX_ AV *av, I32 key)
     if (SvRMAGICAL(av)) {
         const MAGIC * const tied_magic
 	    = mg_find((const SV *)av, PERL_MAGIC_tied);
-        if (tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata)) {
+        const MAGIC * const regdata_magic
+            = mg_find((const SV *)av, PERL_MAGIC_regdata);
+        if (tied_magic || regdata_magic) {
 	    SV * const sv = sv_newmortal();
             MAGIC *mg;
             /* Handle negative array indices 20020222 MJD */
@@ -920,9 +922,18 @@ Perl_av_exists(pTHX_ AV *av, I32 key)
                     key += AvFILL(av) + 1;
                     if (key < 0)
                         return FALSE;
+                    else
+                        return TRUE;
                 }
             }
 
+            if(key >= 0 && regdata_magic) {
+                if (key <= AvFILL(av))
+                    return TRUE;
+                else
+                    return FALSE;
+            }
+
             mg_copy(MUTABLE_SV(av), sv, 0, key);
             mg = mg_find(sv, PERL_MAGIC_tiedelem);
             if (mg) {