Thread: Memory problem - malloc, pointers and vector

Originally Posted by tabstop

That's one too many times. The layers in the vector and the layer sent to the undo system contain the same pointer, and cannot both be freed without causing double delete issues.

No, it is not that simple. Each layer contains its own pointer and memory buffer. The layers in the vector gets freed on exit but the one sent to the undo system is not in the vector then so freeing things in the vector doesn't cause any issues the first time around. The second time the vector is filled in the undo pointer starts pointing to the same memory as the vector layer though for some reason so yes they share memory in some way.

Originally Posted by DrSnuggles

The layers in the vector gets freed on exit but the one sent to the undo system is not in the vector then so freeing things in the vector doesn't cause any issues the first time around.

But it's a copy, you said. If you're just copying the pointer, then they point to the same place.

I think I may be confusing myself here a bit too.... I found the issue. The fact that I'm undoing the layer delete makes the undo buffer in fact get the deleted on tool exit because I push back the same layer onto the vector... ahhrg. The strange thing is it did not complain when the undo destructor was called, only later when trying to use the buffer. I just need to check in the undo class if the layer has been pushed back and if so do not delete the buffer.

So problem solved, thanks a lot for helping out!