Bug #52512: Assertion `! is_set()' in Diagnostics_area::set_ok_status

on LOAD DATA

Two problems :
1. LOAD DATA was not checking for SQL errors and was sending an OK
packet even when there were errors reported already. Fixed to check for
SQL errors in addition to the error conditions already detected.
2. There was an over-ambitious assert() on the server to check if the 
protocol is always followed by the client. This can cause crashes on 
debug servers by clients not completing the protocol exchange for some
reason (e.g. --send command in mysqltest). Fixed by keeping the assert
only on client side, since the server always completes the protocol 
exchange.

mysql-test/r/loaddata.result

@@ -502,4 +502,11 @@ SELECT * FROM t1;
 col0
 test
 DROP TABLE t1;
+#
+# Bug #52512 : Assertion `! is_set()' in 
+#  Diagnostics_area::set_ok_status on LOAD DATA
+#
+CREATE TABLE t1 (id INT NOT NULL);
+LOAD DATA LOCAL INFILE 'tb.txt' INTO TABLE t1;
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/loaddata.test

@@ -554,4 +554,24 @@ let $MYSQLD_DATADIR= `select @@datadir`;
 remove_file $MYSQLD_DATADIR/test/t1.txt;
 
 
+--echo #
+--echo # Bug #52512 : Assertion `! is_set()' in 
+--echo #  Diagnostics_area::set_ok_status on LOAD DATA
+--echo #
+
+connect (con1,localhost,root,,test);
+
+CREATE TABLE t1 (id INT NOT NULL);
+--send LOAD DATA LOCAL INFILE 'tb.txt' INTO TABLE t1
+# please keep this is a spearate test file : it's important to have no
+# commands after this one
+
+connection default;
+dirty_close con1;
+
+connect (con1,localhost,root,,test);
+DROP TABLE t1;
+connection default;
+disconnect con1;
+
 --echo End of 5.1 tests

sql/net_serv.cc

@@ -903,7 +903,13 @@ my_real_read(NET *net, size_t *complen)
 		       ("Packets out of order (Found: %d, expected %u)",
 			(int) net->buff[net->where_b + 3],
 			net->pkt_nr));
-#ifdef EXTRA_DEBUG
+            /* 
+              We don't make noise server side, since the client is expected
+              to break the protocol for e.g. --send LOAD DATA .. LOCAL where
+              the server expects the client to send a file, but the client
+              may reply with a new command instead.
+            */
+#if defined (EXTRA_DEBUG) && !defined (MYSQL_SERVER)
             fflush(stdout);
 	    fprintf(stderr,"Error: Packets out of order (Found: %d, expected %d)\n",
 		    (int) net->buff[net->where_b + 3],

sql/sql_load.cc

@@ -940,6 +940,10 @@ read_sep_field(THD *thd, COPY_INFO &info, TABLE_LIST *table_list,
         DBUG_RETURN(1);
       }
     }
+
+    if (thd->is_error())
+      read_info.error= 1;
+
     if (read_info.error)
       break;
     if (skip_lines)