Bug#21383714: Assertion failed: !thd->is_error() in select_lex::prepare()

The problem is caused by a missing error check after calling
fix_length_and_dec() in Item_sum_hybrid::fix_fields().

Author: roylyseng

mysql-test/suite/gis/r/gis_bugs_crashes.result

@@ -6508,3 +6508,8 @@ ST_GeomFromText('MULTIPOLYGON(((-40.314872143936725 -85.6567579487603,-53.147364
                                    '-41.29168745244485 -90.56754012573627,-40.314872143936725 -85.6567579487603)), '
 
 1
+# BUG#21383714: Assertion failed: !thd->is_error() in select_lex::prepare
+CREATE TABLE t(a INTEGER);
+SELECT 1 FROM t WHERE 1 > SOME (SELECT POINT(1,1) FROM t);
+ERROR HY000: Incorrect arguments to min(
+DROP TABLE t;

mysql-test/suite/gis/t/gis_bugs_crashes.test

@@ -6333,3 +6333,11 @@ SELECT ST_IsValid(
                                    '((-2.6035109435630504 -13.058121512403435,26.839412016794036 43.97610638055074, '
                                      '26.974733141577826 43.72289807427111,26.97470368529088 43.722907009738066, '
                                      '-2.6035109435630504 -13.058121512403435)))'));
+
+--echo # BUG#21383714: Assertion failed: !thd->is_error() in select_lex::prepare
+
+CREATE TABLE t(a INTEGER);
+--error ER_WRONG_ARGUMENTS
+SELECT 1 FROM t WHERE 1 > SOME (SELECT POINT(1,1) FROM t);
+DROP TABLE t;
+

sql/item_sum.cc

@@ -1326,6 +1326,8 @@ Item_sum_hybrid::fix_fields(THD *thd, Item **ref)
   result_field=0;
   null_value=1;
   fix_length_and_dec();
+  if (thd->is_error())
+    return true;
   item= item->real_item();
   if (item->type() == Item::FIELD_ITEM)
     hybrid_field_type= ((Item_field*) item)->field->type();