[UFO-devel] ufo::UObject::trackPointer()

[Andreas B. <b_...@gm...>]

Hi
there is a problem with ufo::UObject::trackPointer() versus 
ufo::UObject::releasePointer():
trackPointer() adds and references the given pointer unconditionally.
However releasePointer() _releases_ the pointer once, but _removes_ it as 
often as it appears in the list.

So something like
  trackPointer(foo);
  trackPointer(foo);
  releasePointer(foo);
causes a memory leak: even if you have a second releasePointer(foo) in the 
code, it won't be able to actually release the pointer.

ufo::UObject::releasePointer() also doesn't give any warning about this, so 
that such a bug would be very hard to find. The attached patch is an example 
of such a warning.
I propose to additionally call unreference() as often as actually required 
(i.e. oldsize - m_pointers.size() times). With such a patch the above error 
message may not be required, depending on whether this kind of use is 
supposed to be allowed.

Last but not least:
ufo::UComboBox c'tors trigger this bug:
  trackPointer(m_textEdit);
  add(getTextEdit());
where getTextEdit() returns m_textEdit. ufo::UWidget::addImpl() calls 
trackPointer() nearly unconditionally and always does in this case.

CU
Andi