memory leak fix proposal

[markulrich1966]

Hello,

When using idesk in combination with an external background-changing script (like icewmbg cycling wallpapers every 20 seconds), idesk's memory usage balloons rapidly up to 2-3 GBs within a short period.

The root cause is located in src/XDesktopContainer.cpp inside XDesktopContainer::initXWin().
Currently, idesk registers for root window changes via:
XSelectInput( display, rootWindow, PropertyChangeMask| SubstructureNotifyMask);

Since idesk ignores most of these background/structure change events in its switch-case loops, the raw X11 event structures pile up endlessly inside Xlib's internal event queue, flooding the process heap and creating a massive memory leak.

Fix applied and verified:
Changing the mask to 0 (or removing PropertyChangeMask and SubstructureNotifyMask) stops the X server from flooding the queue, safely stabilizing idesk's memory footprint at a flat ~31 MB without affecting icon functionality or layer styling.

Modified code section in src/XDesktopContainer.cpp:

void XDesktopContainer::initXWin()
{
     // ...
     prop.nitems = strlen(name);
     XSetTextProperty(display, rootWindow, &prop, start);
     
     // FIX: Remove PropertyChangeMask and SubstructureNotifyMask to prevent event flood leak
     XSelectInput( display, rootWindow, 0 );
     
     XSync(display, false);
}

Please consider merging this fix or updating the root window event mask to prevent this severe memory leak for users with dynamic wallpapers.

Please note: I am not a C++ coder, so solved this using the gemini AI from google.

Best regards!
Mark

[markulrich1966]

I documented the whole discussion, but it is in german. Gemini suggested some other potential leaks, but they did not solve my issue. I uploaded the complete modified sourcecode including compiled binary (Linux Mint 22.3) to: https://schinkenpizza.de/linuxfiles/idesk0.7.9bugfixed/

Cheers, Mark