[gtkada] Ctree memory leak.

[RAMatthews]

I have noticed that Ctree in versions 1.2.10 and 1.2.11 has a fault
in freeing row data - this leads to a memory leak.

In gtk-ctree.adb we have the package Row_Data and in there we have
the procedure Free_Data:

   procedure Free_Data (Data : Data_Type_Access) is
      Local_Data : Data_Type_Access;
   begin
      Deallocate_Data_Type (Local_Data);
   end Free_Data;

Note that Deallocate_Data_Type is an instantiation of 
Unchecked_Deallocation.

Clearly it is trying to deallocate a local variable that has not
been set to anything - that is we are deallocating null.

I have modified my local copy of the procedure to the following:

   procedure Free_Data (Data : Data_Type_Access) is
      Local_Data : Data_Type_Access;
   begin
      Local_Data := Data;
      Deallocate_Data_Type (Local_Data);
   end Free_Data;

I have found that this works - indeed use of Debug_Pools shows that a
memory leak no longer happens.

Robert A. Matthews