Add MATLAB Tests CI and fix double free problem in update

[traversaro]

Adding a CI now that MATLAB is available on GitHub Actions to avoid problems such as #5 in the future.

Just adding the tests reproduced the problem experienced by @HosameldinMohamed in #5 (see tests failing in https://github.com/ami-iit/osqp-matlab-cmake-buildsystem/actions/runs/1915933780 with "double free" error), so the used osqp commit has been updated to point to the newest commit from osqp/osqp-matlab#34 .

We also bumped the version to 0.6.2.2 to be ready to do a release once this is merged.

[traversaro]

@HosameldinMohamed the PR is ready for review.

[HosameldinMohamed]

Great @traversaro! I don't understand yet the patches you're doing in the upstream repo. But I got what you did here, really impressive!

It's cool that the Tests CI executes the tests available upstream!

Thanks!

[traversaro]

I don't understand yet the patches you're doing in the upstream repo

Sorry, then I was not clear in osqp/osqp-matlab#34 . The idea is that matlab has its own allocator that you can use in place of malloc and calloc from the C standard library, that are called mxMalloc and mxCalloc. Whenever you allocate an area of memory with malloc you need to free it with free, and when you allocate an area of memory with mxMalloc you need to free it with mxFree . In osqp, there is a function called c_malloc that is defined at malloc in some cases (see https://github.com/osqp/osqp/blob/0b34f2ef5c5eec314e7945762e1c8167e937afbd/include/glob_opts.h#L69) or mxMalloc in others (see https://github.com/osqp/osqp/blob/0b34f2ef5c5eec314e7945762e1c8167e937afbd/include/glob_opts.h#L29). However, in many cases the areas allocated with c_malloc was freed was mxFree, that is ok as long as c_malloc is actually mxAlloc , but it is not anymore when c_malloc is actually malloc.

[HosameldinMohamed]

Sorry, then I was not clear in osqp/osqp-matlab#34

No it's because I am not yet familiar with the whole MATLAB-C integration thing.

Thanks, this explanation helps a lot.