MDEV-17257 Server crashes in Item::field_type_for_temporal_comparison or in get_datetime_value on SELECT with YEAR field and IN

1 files changed, 12 insertions, 3 deletions

diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 49bbee9edd2..bdef3c1a89f 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -4172,11 +4172,20 @@ void Item_func_in::fix_length_and_dec()
       if (field_item->field_type() ==  MYSQL_TYPE_LONGLONG ||
           field_item->field_type() ==  MYSQL_TYPE_YEAR)
       {
-        bool all_converted= TRUE;
+        bool all_converted= true;
         for (arg=args+1, arg_end=args+arg_count; arg != arg_end ; arg++)
         {
-           if (!convert_const_to_int(thd, field_item, &arg[0]))
-            all_converted= FALSE;
+          /*
+            Explicit NULLs should not affect data cmp_type resolution:
+            - we ignore NULLs when calling collect_cmp_type()
+            - we ignore NULLs here
+            So this expression:
+              year_column IN (DATE'2001-01-01', NULL)
+            switches from TIME_RESULT to INT_RESULT.
+          */
+          if (arg[0]->type() != Item::NULL_ITEM &&
+              !convert_const_to_int(thd, field_item, &arg[0]))
+           all_converted= false;
         }
         if (all_converted)
           cmp_type= INT_RESULT;