ha_myisam::index_first(uchar*)") at assert.c:81

Single-table DELETE crash/assertion similar to single-table
UPDATE bug 14272.

Same resolution as for the bug 14272:
Don't run index scan when we should use quick select.
This could cause failures because there are table handlers (like federated)
that support quick select scanning but do not support index scanning.


mysql-test/r/delete.result:
  Test case for bug #53450.
mysql-test/t/delete.test:
  Test case for bug #53450.
sql/sql_delete.cc:
  Bug #53450: Crash / assertion "virtual int
              ha_myisam::index_first(uchar*)") at assert.c:81
  
  The mysql_delete function has been modified to not to use
  init_read_record_idx instead of init_read_record for the
  quick select.