BUG#19618: Crash for unsigned_col NOT IN (-1, ... )

- When manually constructing a SEL_TREE for "t.key NOT IN(...)", take into account that 
  get_mm_parts may return a tree with type SEL_TREE::IMPOSSIBLE
- Added missing OOM checks
- Added comments

1 files changed, 12 insertions, 0 deletions

diff --git a/mysql-test/t/func_in.test b/mysql-test/t/func_in.test
index 351d1fc2c92..8ddf1fbe314 100644
--- a/mysql-test/t/func_in.test
+++ b/mysql-test/t/func_in.test
@@ -220,3 +220,15 @@ set @str=NULL;
 drop table t2;
 drop table t1;
 
+# BUG#19618: Crash in range optimizer for 
+#   "unsigned_keypart NOT IN(negative_number,...)" 
+#   (introduced in fix BUG#15872) 
+create table t1 (
+  some_id smallint(5) unsigned,
+  key (some_id)
+);
+insert into t1 values (1),(2);
+select some_id from t1 where some_id not in(2,-1);
+select some_id from t1 where some_id not in(-4,-1,-4);
+select some_id from t1 where some_id not in(-4,-1,3423534,2342342);
+drop table t1;