bk commit into 5.0 tree (jimw:1.2200) BUG#16494

[Jim Winstead]

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ChangeSet
  1.2200 06/06/26 16:59:52 jimw@stripped +3 -0
  Bug #16494: Updates that set a column to NULL fail sometimes
  
   When building the UPDATE query to send to the remote server, the
   federated storage engine built the query incorrectly if it was updating
   a field to be NULL.
  

  sql/ha_federated.cc
    1.61 06/06/26 16:59:49 jimw@stripped +7 -10
    Fix logic of how fields are added to SET and WHERE clauses of an
    UPDATE statement. Fields that were NULL were being handled incorrectly.
    Also reorganizes the code a little bit so the update of the two
    clauses is consistent.

  mysql-test/t/federated.test
    1.23 06/06/26 16:59:49 jimw@stripped +17 -0
    Add new regression test

  mysql-test/r/federated.result
    1.27 06/06/26 16:59:49 jimw@stripped +16 -0
    Add new results

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	jimw
# Host:	rama.(none)
# Root:	/home/jimw/my/mysql-5.0-16494

--- 1.26/mysql-test/r/federated.result	2006-02-28 02:17:35 -08:00
+++ 1.27/mysql-test/r/federated.result	2006-06-26 16:59:49 -07:00
@@ -1601,6 +1601,22 @@ fld_cid	fld_name	fld_parentid	fld_delt
 5	Torkel	0	0
 DROP TABLE federated.t1;
 DROP TABLE federated.bug_17377_table;
+create table t1 (id int not null auto_increment primary key, val int);
+create table t1
+(id int not null auto_increment primary key, val int) engine=federated
+connection='mysql://root@stripped:9308/test/t1';
+insert into t1 values (1,0),(2,0);
+update t1 set val = NULL where id = 1;
+select * from t1;
+id	val
+1	NULL
+2	0
+select * from t1;
+id	val
+1	NULL
+2	0
+drop table t1;
+drop table t1;
 DROP TABLE IF EXISTS federated.t1;
 DROP DATABASE IF EXISTS federated;
 DROP TABLE IF EXISTS federated.t1;

--- 1.22/mysql-test/t/federated.test	2006-02-28 02:17:35 -08:00
+++ 1.23/mysql-test/t/federated.test	2006-06-26 16:59:49 -07:00
@@ -1309,5 +1309,22 @@ DROP TABLE federated.t1;
 connection slave;
 DROP TABLE federated.bug_17377_table;
 
+#
+# Bug #16494: Updates that set a column to NULL fail sometimes
+#
+connection slave;
+create table t1 (id int not null auto_increment primary key, val int);
+connection master;
+eval create table t1
+  (id int not null auto_increment primary key, val int) engine=federated
+  connection='mysql://root@stripped:$SLAVE_MYPORT/test/t1';
+insert into t1 values (1,0),(2,0);
+update t1 set val = NULL where id = 1;
+select * from t1;
+connection slave;
+select * from t1;
+drop table t1;
+connection master;
+drop table t1;
 
 source include/federated_cleanup.inc;

--- 1.60/sql/ha_federated.cc	2006-02-28 02:17:35 -08:00
+++ 1.61/sql/ha_federated.cc	2006-06-26 16:59:49 -07:00
@@ -1857,8 +1857,8 @@ int ha_federated::update_row(const byte 
   In this loop, we want to match column names to values being inserted
   (while building INSERT statement).
 
-  Iterate through table->field (new data) and share->old_filed (old_data)
-  using the same index to created an SQL UPDATE statement, new data is
+  Iterate through table->field (new data) and share->old_field (old_data)
+  using the same index to create an SQL UPDATE statement. New data is
   used to create SET field=value and old data is used to create WHERE
   field=oldvalue
  */
@@ -1870,30 +1870,28 @@ int ha_federated::update_row(const byte 
     update_string.append(FEDERATED_EQ);
 
     if ((*field)->is_null())
-      new_field_value.append(FEDERATED_NULL);
+      update_string.append(FEDERATED_NULL);
     else
     {
       /* otherwise = */
       (*field)->val_str(&new_field_value);
       (*field)->quote_data(&new_field_value);
-
-      if (!field_in_record_is_null(table, *field, (char*) old_data))
-        where_string.append(FEDERATED_EQ);
+      update_string.append(new_field_value);
+      new_field_value.length(0);
     }
 
     if (field_in_record_is_null(table, *field, (char*) old_data))
       where_string.append(FEDERATED_ISNULL);
     else
     {
+      where_string.append(FEDERATED_EQ);
       (*field)->val_str(&old_field_value,
                         (char*) (old_data + (*field)->offset()));
       (*field)->quote_data(&old_field_value);
       where_string.append(old_field_value);
+      old_field_value.length(0);
     }
 
-    update_string.append(new_field_value);
-    new_field_value.length(0);
-
     /*
       Only append conjunctions if we have another field in which
       to iterate
@@ -1903,7 +1901,6 @@ int ha_federated::update_row(const byte 
       update_string.append(FEDERATED_COMMA);
       where_string.append(FEDERATED_AND);
     }
-    old_field_value.length(0);
   }
   update_string.append(FEDERATED_WHERE);
   update_string.append(where_string);