merge of 5.1-main into mysql-trunk.

Changes to ha_innodb.cc are not propagated to plugin, they will come back
via Oracle/Innobase if needed.

3 files changed, 25 insertions, 2 deletions

diff --git a/storage/myisammrg/ha_myisammrg.cc b/storage/myisammrg/ha_myisammrg.cc
index 40784e81760..83a46ca9f9f 100644
--- a/storage/myisammrg/ha_myisammrg.cc
+++ b/storage/myisammrg/ha_myisammrg.cc
@@ -907,7 +907,6 @@ int ha_myisammrg::info(uint flag)
     */
     mrg_info.errkey= MAX_KEY;
   }
-  errkey= mrg_info.errkey;
   table->s->keys_in_use.set_prefix(table->s->keys);
   stats.mean_rec_length= mrg_info.reclength;
   
@@ -957,6 +956,11 @@ int ha_myisammrg::info(uint flag)
              min(file->keys, table->s->key_parts));
     }
   }
+  if (flag & HA_STATUS_ERRKEY)
+  {
+    errkey= mrg_info.errkey;
+    my_store_ptr(dup_ref, ref_length, mrg_info.dupp_key_pos);
+  }
   return 0;
 }
 
diff --git a/storage/myisammrg/ha_myisammrg.h b/storage/myisammrg/ha_myisammrg.h
index 21d41c9d75a..790aa15e90a 100644
--- a/storage/myisammrg/ha_myisammrg.h
+++ b/storage/myisammrg/ha_myisammrg.h
@@ -44,7 +44,8 @@ class ha_myisammrg: public handler
 	    HA_NULL_IN_KEY | HA_CAN_INDEX_BLOBS | HA_FILE_BASED |
             HA_ANY_INDEX_MAY_BE_UNIQUE | HA_CAN_BIT_FIELD |
             HA_HAS_RECORDS |
-            HA_NO_COPY_ON_ALTER);
+            HA_NO_COPY_ON_ALTER |
+            HA_DUPLICATE_POS);
   }
   ulong index_flags(uint inx, uint part, bool all_parts) const
   {
diff --git a/storage/myisammrg/myrg_info.c b/storage/myisammrg/myrg_info.c
index 7ea2dbf58e3..1930351ec8f 100644
--- a/storage/myisammrg/myrg_info.c
+++ b/storage/myisammrg/myrg_info.c
@@ -58,9 +58,27 @@ int myrg_status(MYRG_INFO *info,register MYMERGE_INFO *x,int flag)
     x->reclength= info->reclength;
     x->options= info->options;
     if (current_table)
+    {
+      /*
+        errkey is set to the index number of the myisam tables. But
+        since the MERGE table can have less keys than the MyISAM
+        tables, errkey cannot be be used as an index into the key_info
+        on the server. This value will be overwritten with MAX_KEY by
+        the MERGE engine.
+      */
       x->errkey= current_table->table->errkey;
+      /*
+        Calculate the position of the duplicate key to be the sum of the
+        offset of the myisam file and the offset into the file at which
+        the duplicate key is located.
+      */
+      x->dupp_key_pos= current_table->file_offset + current_table->table->dupp_key_pos;
+    }
     else
+    {
       x->errkey= 0;
+      x->dupp_key_pos= 0;
+    }
     x->rec_per_key = info->rec_per_key_part;
   }
   DBUG_RETURN(0);