Memory leak due to missing deallocator

[sergei-mironov]

Ref #30

[sergei-mironov]

Status:

1. Merged workaround fix memory leak in XKeyboard::build_layout #30
2. Waiting for upstream reply for https://bugs.freedesktop.org/show_bug.cgi?id=110696 https://gitlab.freedesktop.org/xorg/lib/libxkbfile/issues/6

Note meaningful comment by @szaszm #30 (comment)

[alexandersolovyov]

Actually, all needed functions are already there. It can be done in two ways:

1. XkbRf_getNamesProp() can receive XkbRF_VarDefsPtr instead of reference toXkbRF_VarDefsRec. Then, memory must be cleared with XkbRF_Free(vdr, True).
2. If You are using XkbRF_GetNamesProp() with a reference toXkbRF_VarDefsRec, memory should be returned using XkbRF_Free(&vdr, False).

libxkbfile is written in C, so they can not add any destructor. It is done by analogy with X library, where function XFree() must be used to return memory for all entities created by functions of this library.

You can see it yourself, search for XkbRF_Free and XkbRf_getNamesProp in source code:
XKBrules.h
maprules.c

Also be attentive when functions allocates memory for other pointers ;-)

Maybe I will do next pull request to close this issue soon.

[sergei-mironov]

Good news, XkbRF_Free looks like a correct solution. Thank you for the information. I'll be happy to accept the PR.

[alexandersolovyov]

I made a mistake here. XkbRF_Free is made only for XkbRF_RulesPtr, not for XkbRF_VarDefsPtr. The best decision for freeing XkbRF_VarDefsPtr is already applied.

[sergei-mironov]

OK. Related sources for reference is here https://github.com/mattl/opensource.apple.com/blob/master/src/X11libs/X11libs-60.2/libxkbfile/libxkbfile-1.0.7/include/X11/extensions/XKBrules.h#L170