Fix value of YEAR field when set from a non-numeric string. (Bug #6067)

mysql-test/t/type_date.test:
  Add new regression test
mysql-test/r/type_date.result:
  Add result
sql/field.cc:
  Set YEAR to 0 when set to a non-numeric string, not 2000,
  and issue a warning.

mysql-test/r/type_date.result

@@ -96,3 +96,11 @@ f2
 19781126
 19781126
 DROP TABLE t1, t2, t3;
+CREATE TABLE t1 (y YEAR);
+INSERT INTO t1 VALUES ('abc');
+Warnings:
+Warning	1265	Data truncated for column 'y' at row 1
+SELECT * FROM t1;
+y
+0000
+DROP TABLE t1;

mysql-test/t/type_date.test

@@ -107,3 +107,10 @@ SELECT * FROM t2;
 SELECT * FROM t3;
 
 DROP TABLE t1, t2, t3;
+
+# Test that setting YEAR to invalid string results in default value, not
+# 2000. (Bug #6067)
+CREATE TABLE t1 (y YEAR);
+INSERT INTO t1 VALUES ('abc');
+SELECT * FROM t1;
+DROP TABLE t1;

sql/field.cc

@@ -3511,9 +3511,17 @@ void Field_time::sql_type(String &res) const
 
 int Field_year::store(const char *from, uint len,CHARSET_INFO *cs)
 {
-  int not_used;				// We can ignore result from str2int
+  int err;
   char *end;
-  long nr= my_strntol(cs, from, len, 10, &end, &not_used);
+  long nr= my_strntol(cs, from, len, 10, &end, &err);
+
+  if (err)
+  {
+    if (table->in_use->count_cuted_fields)
+      set_warning(MYSQL_ERROR::WARN_LEVEL_WARN, ER_WARN_DATA_TRUNCATED, 1);
+    *ptr= 0;
+    return 0;
+  }
 
   if (nr < 0 || nr >= 100 && nr <= 1900 || nr > 2155)
   {