From 4cdbe25a6b3f3f47b245a15ed7ce4d584c8ef9b1 Mon Sep 17 00:00:00 2001
From: "evgen@moonbone.local" <>
Date: Tue, 12 Jun 2007 01:41:23 +0400
Subject: [PATCH] Bug#28904: INSERT .. ON DUPLICATE was silently updating rows
 when it shouldn't.

When the INSERT .. ON DUPLICATE KEY UPDATE has to update a matched row but
the new data is the same as in the record then it returns as if
no rows were inserted or updated. Nevertheless the row is silently
updated. This leads to a situation when zero updated rows are reported
in the case when data has actually been changed.

Now the write_record function updates a row only if new data differs from
that in the record.
---
 mysql-test/r/insert_update.result | 14 ++++++++++++++
 mysql-test/t/insert_update.test   | 16 ++++++++++++++++
 sql/sql_insert.cc                 | 28 ++++++++++++++--------------
 3 files changed, 44 insertions(+), 14 deletions(-)

diff --git a/mysql-test/r/insert_update.result b/mysql-test/r/insert_update.result
index b3bca7517f3..20cde86101e 100644
--- a/mysql-test/r/insert_update.result
+++ b/mysql-test/r/insert_update.result
@@ -393,3 +393,17 @@ id	c1	cnt
 1	0	3
 2	2	1
 DROP TABLE t1;
+create table t1(f1 int primary key,
+f2 timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP);
+insert into t1(f1) values(1);
+select @stamp1:=f2 from t1;
+@stamp1:=f2
+#
+insert into t1(f1) values(1) on duplicate key update f1=1;
+select @stamp2:=f2 from t1;
+@stamp2:=f2
+#
+select if( @stamp1 = @stamp2, "correct", "wrong");
+if( @stamp1 = @stamp2, "correct", "wrong")
+correct
+drop table t1;
diff --git a/mysql-test/t/insert_update.test b/mysql-test/t/insert_update.test
index 725fbdb25d7..67108744ec6 100644
--- a/mysql-test/t/insert_update.test
+++ b/mysql-test/t/insert_update.test
@@ -290,3 +290,19 @@ INSERT IGNORE INTO t1 (id,c1) SELECT * FROM t2
 SELECT * FROM t1;
 
 DROP TABLE t1;
+
+#
+# Bug#28904: INSERT .. ON DUPLICATE was silently updating rows when it
+#            shouldn't.
+#
+create table t1(f1 int primary key,
+ f2 timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP);
+insert into t1(f1) values(1);
+--replace_column 1 #
+select @stamp1:=f2 from t1;
+--sleep 2
+insert into t1(f1) values(1) on duplicate key update f1=1;
+--replace_column 1 #
+select @stamp2:=f2 from t1;
+select if( @stamp1 = @stamp2, "correct", "wrong");
+drop table t1;
diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index f3ed3ebab24..228fc8860ae 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -1404,23 +1404,18 @@ int write_record(THD *thd, TABLE *table,COPY_INFO *info)
           goto before_trg_err;
 
         table->file->restore_auto_increment();
-        if ((error=table->file->update_row(table->record[1],table->record[0])))
-        {
-          if ((error == HA_ERR_FOUND_DUPP_KEY) && info->ignore)
-          {
-            goto ok_or_after_trg_err;
-          }
-          goto err;
-        }
-
-        if (table->next_number_field)
-          table->file->adjust_next_insert_id_after_explicit_value(
-            table->next_number_field->val_int());
-        info->touched++;
-
         if ((table->file->table_flags() & HA_PARTIAL_COLUMN_READ) ||
             compare_record(table, thd->query_id))
         {
+          if ((error=table->file->update_row(table->record[1],table->record[0])))
+          {
+            if ((error == HA_ERR_FOUND_DUPP_KEY) && info->ignore)
+            {
+              goto ok_or_after_trg_err;
+            }
+            goto err;
+          }
+
           info->updated++;
           trg_error= (table->triggers &&
                       table->triggers->process_triggers(thd, TRG_EVENT_UPDATE,
@@ -1429,6 +1424,11 @@ int write_record(THD *thd, TABLE *table,COPY_INFO *info)
           info->copied++;
         }
 
+        if (table->next_number_field)
+          table->file->adjust_next_insert_id_after_explicit_value(
+            table->next_number_field->val_int());
+        info->touched++;
+
         goto ok_or_after_trg_err;
       }
       else /* DUP_REPLACE */