Bug #11765218 58157: INNODB LOCKS AN UNMATCHED ROW EVEN THOUGH USING

RBR AND RC

Description: When scanning and locking rows with < or <=, InnoDB locks
the next row even though row based binary logging and read committed
is used.

Solution: In the handler, when the row is identified to fall outside
of the range (as specified in the query predicates), then request the
storage engine to unlock the row (if possible). This is done in
handler::read_range_first() and handler::read_range_next().

sql/handler.cc

@@ -4287,7 +4287,19 @@ int handler::read_range_first(const key_range *start_key,
 		? HA_ERR_END_OF_FILE
 		: result);
 
-  DBUG_RETURN (compare_key(end_range) <= 0 ? 0 : HA_ERR_END_OF_FILE);
+  if (compare_key(end_range) <= 0)
+  {
+    DBUG_RETURN(0);
+  }
+  else
+  {
+    /*
+      The last read row does not fall in the range. So request
+      storage engine to release row lock if possible.
+    */
+    unlock_row();
+    DBUG_RETURN(HA_ERR_END_OF_FILE);
+  }
 }
 
 
@@ -4319,7 +4331,20 @@ int handler::read_range_next()
   result= index_next(table->record[0]);
   if (result)
     DBUG_RETURN(result);
-  DBUG_RETURN(compare_key(end_range) <= 0 ? 0 : HA_ERR_END_OF_FILE);
+
+  if (compare_key(end_range) <= 0)
+  {
+    DBUG_RETURN(0);
+  }
+  else
+  {
+    /*
+      The last read row does not fall in the range. So request
+      storage engine to release row lock if possible.
+    */
+    unlock_row();
+    DBUG_RETURN(HA_ERR_END_OF_FILE);
+  }
 }