ha_innodb.cc:

  Add some comments
ha_innodb.h:
  Remove the flag HA_NOT_READ_PREFIX_LAST from ha_innodb.h: InnoDB has supported this from the start, but not tested yet

sql/ha_innodb.cc

@@ -2079,7 +2079,10 @@ ha_innobase::index_read(
 					start or end of index; this can
 					also contain an InnoDB row id, in
 					which case key_len is the InnoDB
-					row id length */
+					row id length; the key value can
+					also be a prefix of a full key value,
+					and the last column can be a prefix
+					of a full column */
 	uint			key_len,/* in: key value length */
 	enum ha_rkey_function find_flag)/* in: search flags from my_base.h */
 {
@@ -2169,24 +2172,24 @@ ha_innobase::index_read(
 	DBUG_RETURN(error);
 }
 
-
-/*
-  The following functions works like index_read, but it find the last
-  row with the current index prefix.
-  This code is disabled until Heikki has verified that InnoDB support the
-  HA_READ_PREFIX_LAST flag and removed the HA_NOT_READ_PREFIX_LAST
-  flag from ha_innodb.h
-*/
+/***********************************************************************
+The following functions works like index_read, but it find the last
+row with the current key value or prefix. */
 
 int
-ha_innobase::index_read_last(mysql_byte *buf,
-			     const mysql_byte *key_ptr,
-			     uint key_len)
+ha_innobase::index_read_last(
+/*=========================*/
+			           /* out: 0, HA_ERR_KEY_NOT_FOUND, or an
+				   error code */
+        mysql_byte*       buf,     /* out: fetched row */
+        const mysql_byte* key_ptr, /* in: key value, or a prefix of a full
+				   key value */
+	uint              key_len) /* in: length of the key val or prefix
+				   in bytes */
 {
-  return index_read(buf, key_ptr, key_len, HA_READ_PREFIX_LAST);
+        return(index_read(buf, key_ptr, key_len, HA_READ_PREFIX_LAST));
 }
 
-
 /************************************************************************
 Changes the active index of a handle. */
 

sql/ha_innodb.h

@@ -96,7 +96,7 @@ class ha_innobase: public handler
 	ulong index_flags(uint idx) const
 	{
 	  return (HA_READ_NEXT | HA_READ_PREV | HA_READ_ORDER |
-		  HA_NOT_READ_PREFIX_LAST | HA_KEY_READ_ONLY);
+		  HA_KEY_READ_ONLY);
 	}
   	uint max_record_length() const { return HA_MAX_REC_LENGTH; }
   	uint max_keys()          const { return MAX_KEY; }