Fix for bug #22271: data casting may affect data stored in the next column(s?)

Using wrong filling value may cause unneeded extra bit rewriting.

Fix: use proper value to fill uneven bits.

mysql-test/r/type_bit.result

@@ -602,4 +602,12 @@ NULL	NULL
 0	0
 11111111	11111111
 drop table bug15583;
+create table t1(a bit(1), b smallint unsigned);
+insert into t1 (b, a) values ('2', '1');
+Warnings:
+Warning	1264	Out of range value adjusted for column 'a' at row 1
+select hex(a), b from t1;
+hex(a)	b
+1	2
+drop table t1;
 End of 5.0 tests

mysql-test/t/type_bit.test

@@ -252,5 +252,13 @@ select hex(b + 0), bin(b + 0), oct(b + 0), hex(n), bin(n), oct(n) from bug15583;
 select conv(b, 10, 2), conv(b + 0, 10, 2) from bug15583;
 drop table bug15583;
 
+#
+# Bug #22271: data casting may affect data stored in the next column(s?)
+#
+
+create table t1(a bit(1), b smallint unsigned);
+insert into t1 (b, a) values ('2', '1');
+select hex(a), b from t1;
+drop table t1;
 
 --echo End of 5.0 tests

sql/field.cc

@@ -7921,7 +7921,7 @@ int Field_bit::store(const char *from, uint length, CHARSET_INFO *cs)
       (delta == -1 && (uchar) *from > ((1 << bit_len) - 1)) ||
       (!bit_len && delta < 0))
   {
-    set_rec_bits(0xff, bit_ptr, bit_ofs, bit_len);
+    set_rec_bits((1 << bit_len) - 1, bit_ptr, bit_ofs, bit_len);
     memset(ptr, 0xff, bytes_in_rec);
     if (table->in_use->really_abort_on_warning())
       set_warning(MYSQL_ERROR::WARN_LEVEL_ERROR, ER_DATA_TOO_LONG, 1);