[perl #129880] regcomp.c:6207: SV *S_concat_pat(RExC_state_t *const,SV *, SV **const, int, OP *, _Bool *, SV *): Assertion `oplist->op_type ==OP_PADAV || oplist->op_type == OP_RV2AV' failed

# New Ticket Created by  Brian Carpenter 
# Please include the string:  [perl #129880]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=129880 >


Triggered in Perl v5.25.6 (v5.25.5-104-gaff2be5).

perl -e 'qr{(?{}){@0{@}}@0}'

perl: regcomp.c:6207: SV *S_concat_pat(RExC_state_t *const, SV *, SV
**const, int, OP *, _Bool *, SV *): Assertion `oplist->op_type == OP_PADAV
|| oplist->op_type == OP_RV2AV' failed.
Aborted

• [perl #129880] regcomp.c:6207: SV *S_concat_pat(RExC_state_t *const,SV *, SV **const, int, OP *, _Bool *, SV *): Assertion `oplist->op_type ==OP_PADAV || oplist->op_type == OP_RV2AV' failed by Hugo van der Sanden via RT
• Re: [perl #129880] regcomp.c:6207: SV *S_concat_pat(RExC_state_t*const, SV *, SV **const, int, OP *, _Bool *, SV *): Assertion`oplist->op_type == OP_PADAV || oplist->op_type == OP_RV2AV' failed by Brian C.
• [perl #129880] regcomp.c:6207: SV *S_concat_pat(RExC_state_t *const,SV *, SV **const, int, OP *, _Bool *, SV *): Assertion `oplist->op_type ==OP_PADAV || oplist->op_type == OP_RV2AV' failed by Brian Carpenter