row_sel_store_mysql_rec(): Convert NULL true VARCHAR columns

correctly.


innobase/row/row0sel.c:
  Initialize NULL true VARCHAR columns with NUL bytes, as that is
  what the columns will contain in handler::write_row().  (Bug #12186)
mysql-test/r/innodb.result:
  Update table checksums to reflect the new handling of
  true VARCHAR columns that are NULL.

innobase/row/row0sel.c

@@ -2524,11 +2524,19 @@ row_sel_store_mysql_rec(
 					(byte) (templ->mysql_null_bit_mask);
 			switch (templ->type) {
 			case DATA_VARCHAR:
-			case DATA_CHAR:
 			case DATA_BINARY:
+			case DATA_VARMYSQL:
+				if (templ->mysql_type
+				    == DATA_MYSQL_TRUE_VARCHAR) {
+					/* This is a >= 5.0.3 type
+					true VARCHAR.  Zero the field. */
+					pad_char = 0x00;
+					break;
+				}
+				/* Fall through */
+			case DATA_CHAR:
 			case DATA_FIXBINARY:
 			case DATA_MYSQL:
-			case DATA_VARMYSQL:
 			        /* MySQL pads all non-BLOB and non-TEXT
 				string types with space ' ' */
 				if (UNIV_UNLIKELY(templ->mbminlen == 2)) {

mysql-test/r/innodb.result

@@ -1452,16 +1452,16 @@ Error	1146	Table 'test.t4' doesn't exist
 checksum table t1, t2, t3, t4;
 Table	Checksum
 test.t1	2948697075
-test.t2	1157260244
-test.t3	1157260244
+test.t2	3835700799
+test.t3	3835700799
 test.t4	NULL
 Warnings:
 Error	1146	Table 'test.t4' doesn't exist
 checksum table t1, t2, t3, t4 extended;
 Table	Checksum
 test.t1	3092701434
-test.t2	1157260244
-test.t3	1157260244
+test.t2	3835700799
+test.t3	3835700799
 test.t4	NULL
 Warnings:
 Error	1146	Table 'test.t4' doesn't exist