From 68af862c77c8038e4f9b385433bfedb682fbec69 Mon Sep 17 00:00:00 2001
From: "antony@ppcg5.local" <>
Date: Fri, 29 Jun 2007 13:55:16 -0700
Subject: [PATCH] add and amend comments for clarity

---
 include/my_base.h   | 5 ++---
 sql/ha_federated.cc | 4 ++++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/my_base.h b/include/my_base.h
index a26217f8050..4ce7a87105d 100644
--- a/include/my_base.h
+++ b/include/my_base.h
@@ -170,9 +170,8 @@ enum ha_extra_function {
   HA_EXTRA_DELETE_CANNOT_BATCH,
   HA_EXTRA_UPDATE_CANNOT_BATCH,
   /*
-    Inform handler that write_row() should immediately report constraint
-    violations because a INSERT...ON DUPLICATE KEY UPDATE is in being
-    performed.
+    Inform handler that an "INSERT...ON DUPLICATE KEY UPDATE" will be
+    executed. This condition is unset by HA_EXTRA_NO_IGNORE_DUP_KEY.
   */
   HA_EXTRA_INSERT_WITH_UPDATE
 };
diff --git a/sql/ha_federated.cc b/sql/ha_federated.cc
index e691831bbc9..8db091669c3 100644
--- a/sql/ha_federated.cc
+++ b/sql/ha_federated.cc
@@ -2555,6 +2555,10 @@ int ha_federated::extra(ha_extra_function operation)
     replace_duplicates= TRUE;
     break;
   case HA_EXTRA_WRITE_CANNOT_REPLACE:
+    /*
+      We use this flag to ensure that we do not create an "INSERT IGNORE"
+      statement when inserting new rows into the remote table.
+    */
     replace_duplicates= FALSE;
     break;
   case HA_EXTRA_INSERT_WITH_UPDATE: