bug #10166 (Signed byte values cause data to be padded)

The AsBinary function returns VARCHAR data type with binary collation.
It can cause problem for clients that treat that kind of data as
different from BLOB type.
So now AsBinary returns BLOB.

mysql-test/t/gis.test

@@ -364,3 +364,10 @@ select (asWKT(geomfromwkb((0x000000000140240000000000004024000000000000))));
 select (asWKT(geomfromwkb((0x010100000000000000000024400000000000002440))));
 
 # End of 4.1 tests
+
+--enable_metadata
+create table t1 (g GEOMETRY);
+select * from t1;
+select asbinary(g) from t1;
+--disable_metadata
+drop table t1;