Created attachment 188685 [details]
Proof of leak

I have an application (glipper) in which I update the menu quite frequently, and I noticed a slow rise in memory usage while running, and I tracked it down to GtkMenuItem.

I noticed this in Ubuntu 10.10 (gtk 2.22.0), but since there were only a few days to 11.04, I decided to wait. I can also confirm the bug in Ubuntu 11.04 (gtk 2.24.4).

Please note that this leak happens only if the GtkMenuItem has a label. There's no leak if it doesn't have a label.

Proof code attached. Glipper is written in Python (with PyGTK), so the first thing I did to track this down was to create the simplest python program that demonstrates the bug. Using my friend Google, I managed to write the same code in Vala and compile it to C (to confirm it doesn't do anything else but create and destroy GtkMenuItem objects). The leak still exists after compiling the C source.

How to test:
1. Start "top", sort by memory (<O> <n> <enter>)
2. Run either the python script or the binary resulting from the Vala or C sources.
3. Watch the program rise in "top". It will take less than a minute to become noticeable.

Reading the source, unless I missed something, I should have at most one GtkMenuItem at any time, so the memory usage should not increase. So far, the workaround is to explicitly destroy the GtkMenuItem, but it's not that convenient.

There may be a similar, but not as evident issue in GtkMenu after removing a GtkMenuItem, but I haven't pursued that possible problem yet. I'll file another bug report if I can confirm the GtkMenu leak it's not just my imagination.