Fix for bug #5134: WHERE x = 'bar' AND x LIKE BINARY 'bar' returns

wrong results

mysql-test/r/binary.result

@@ -80,3 +80,21 @@ NULL
 select b from t1 having binary b like '';
 b
 drop table t1;
+create table t1( firstname char(20), lastname char(20));
+insert into t1 values ("john","doe"),("John","Doe");
+select * from t1 where firstname='john' and firstname like binary 'john';
+firstname	lastname
+john	doe
+select * from t1 where firstname='john' and binary 'john' = firstname;
+firstname	lastname
+john	doe
+select * from t1 where firstname='john' and firstname = binary 'john';
+firstname	lastname
+john	doe
+select * from t1 where firstname='John' and firstname like binary 'john';
+firstname	lastname
+john	doe
+select * from t1 where firstname='john' and firstname like binary 'John';
+firstname	lastname
+John	Doe
+drop table t1;

mysql-test/t/binary.test

@@ -49,3 +49,16 @@ select b from t1 where binary b like '';
 select b from t1 group by binary b like '';
 select b from t1 having binary b like '';
 drop table t1;
+
+#
+# Bug5134: WHERE x = 'bar' AND x LIKE BINARY 'bar' returns wrong results
+#
+
+create table t1( firstname char(20), lastname char(20));
+insert into t1 values ("john","doe"),("John","Doe");
+select * from t1 where firstname='john' and firstname like binary 'john';
+select * from t1 where firstname='john' and binary 'john' = firstname;
+select * from t1 where firstname='john' and firstname = binary 'john';
+select * from t1 where firstname='John' and firstname like binary 'john';
+select * from t1 where firstname='john' and firstname like binary 'John';
+drop table t1;

sql/sql_select.cc

@@ -3371,7 +3371,10 @@ change_cond_ref_to_const(I_List<COND_CMP> *save_list,Item *and_father,
   Item *right_item= func->arguments()[1];
   Item_func::Functype functype=  func->functype();
 
-  if (right_item->eq(field,0) && left_item != value)
+  if (right_item->eq(field,0) && left_item != value &&
+      (left_item->result_type() != STRING_RESULT ||
+       value->result_type() != STRING_RESULT ||
+       left_item->binary == value->binary))
   {
     Item *tmp=value->new_item();
     if (tmp)
@@ -3390,7 +3393,10 @@ change_cond_ref_to_const(I_List<COND_CMP> *save_list,Item *and_father,
 				       func->arguments()[1]->result_type()));
     }
   }
-  else if (left_item->eq(field,0) && right_item != value)
+  else if (left_item->eq(field,0) && right_item != value &&
+           (right_item->result_type() != STRING_RESULT ||
+            value->result_type() != STRING_RESULT ||
+            right_item->binary == value->binary))
   {
     Item *tmp=value->new_item();
     if (tmp)