MDEV-6393: ANALYZE SELECT crashes ... Don't try printing EXPLAIN if we had an error.

mysql-test/r/analyze_stmt.result

@@ -197,3 +197,21 @@ select * from t1;
 a	b
 6	6
 drop table t0, t1;
+#
+# MDEV-6393: ANALYZE SELECT crashes in Explain_query::print_explain with a non-existing column
+#
+create table t1 (i int);
+insert into t1 values (1),(2);
+analyze select a from t1;
+ERROR 42S22: Unknown column 'a' in 'field list'
+analyze delete from t1 where a=2;
+ERROR 42S22: Unknown column 'a' in 'where clause'
+analyze update t1 set a=2;
+ERROR 42S22: Unknown column 'a' in 'field list'
+create table t2 like t1;
+insert into t2 select * from t1;
+analyze update t2,t1 set t2.i=5 where t2.a=t1.a;
+ERROR 42S22: Unknown column 't2.a' in 'where clause'
+analyze delete t1 from t2,t1 where t2.a=t1.a;
+ERROR 42S22: Unknown column 't2.a' in 'where clause'
+drop table t1,t2;

mysql-test/t/analyze_stmt.test

@@ -146,3 +146,28 @@ select * from t1;
 
 drop table t0, t1;
 
+--echo #
+--echo # MDEV-6393: ANALYZE SELECT crashes in Explain_query::print_explain with a non-existing column
+--echo #
+create table t1 (i int);
+insert into t1 values (1),(2);
+--error ER_BAD_FIELD_ERROR
+analyze select a from t1;
+
+--error ER_BAD_FIELD_ERROR
+analyze delete from t1 where a=2;
+
+--error ER_BAD_FIELD_ERROR
+analyze update t1 set a=2;
+
+create table t2 like t1;
+insert into t2 select * from t1;
+
+--error ER_BAD_FIELD_ERROR
+analyze update t2,t1 set t2.i=5 where t2.a=t1.a;
+
+--error ER_BAD_FIELD_ERROR
+analyze delete t1 from t2,t1 where t2.a=t1.a;
+
+drop table t1,t2;
+

sql/sql_parse.cc

@@ -5282,7 +5282,8 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables)
           return 1;
         delete thd->protocol;
         thd->protocol= save_protocol;
-        thd->lex->explain->send_explain(thd);
+        if (!res)
+          thd->lex->explain->send_explain(thd);
 
         if (result != lex->result)
           delete result;