in test main.range_vs_index_merge one path requires named JSON object:
assert.c:0(.annobin_assert.c_end)[0x7fe9d2270a76]
sql/my_json_writer.cc:43(Json_writer::on_start_object())[0x555e284f048a]
sql/my_json_writer.cc:59(Json_writer::start_object())[0x555e284ee6e8]
sql/my_json_writer.h:377(Json_writer_object::Json_writer_object(THD*))[0x555e281dce11]
sql/opt_range.cc:5137(get_best_disjunct_quick(PARAM*, SEL_IMERGE*, double))[0x555e287c576b]
sql/opt_range.cc:5492(merge_same_index_scans(PARAM*, SEL_IMERGE*, TRP_INDEX_MERGE*, double))[0x555e287c6cf6]
sql/opt_range.cc:5287(get_best_disjunct_quick(PARAM*, SEL_IMERGE*, double))[0x555e287c607a]
sql/opt_range.cc:3000(SQL_SELECT::test_quick_select

another one requires unnamed JSON:
mariadbd: /home/name/server/sql/my_json_writer.cc:379: bool Single_line_formatting_helper::on_add_member(const char*, size_t): Assertion `state== INACTIVE || state ==
assert.c:0(.annobin_assert.c_end)[0x7f33d8df8a76]
sql/my_json_writer.cc:380(Single_line_formatting_helper::on_add_member(char const*, unsigned long))[0x558362f6a717]
sql/my_json_writer.cc:150(Json_writer::add_member(char const*, unsigned long))[0x558362f69a91]
sql/my_json_writer.cc:146(Json_writer::add_member(char const*))[0x558362f69a5f]
sql/my_json_writer.h:383(Json_writer_object::Json_writer_object(THD*, char const*))[0x558362ceccaa]
sql/opt_range.cc:5139(get_best_disjunct_quick(PARAM*, SEL_IMERGE*, double))[0x5583632407d0]
sql/opt_range.cc:3000(SQL_SELECT::test_quick_select