Avoid opt_aset_with optimization inside multiple assignment

Previously, since the opt_aset_with optimization was introduced,
use of the opt_aset_with optimization inside multiple assignment
would result in a segfault or incorrect instructions.

Fixes [Bug #21012]

Co-authored-by: Nobuyoshi Nakada <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/iseq.h b/iseq.h
index a0b59c441f..a9af64572e 100644
--- a/iseq.h
+++ b/iseq.h
@@ -119,6 +119,7 @@ struct iseq_compile_data {
       struct iseq_compile_data_storage *storage_current;
     } insn;
     bool in_rescue;
+    bool in_masgn;
     int loopval_popped;	/* used by NODE_BREAK */
     int last_line;
     int label_no;