CCmpSelectable.cpp unit test for buildings without footprint

[elexis]

Reproduce: remove <Footprint> from binaries/data/mods/public/simulation/templates/template_structure_civic_civil_centre.xml and start a game, select the cc.

Stack:

0x000000000052ab6d in CCmpSelectable::RenderSubmit (collector=..., this=0x526b460)
    at ../../../source/simulation2/components/CCmpSelectable.cpp:629
629						m_BuildingOverlay->m_Color = m_Color; // done separately so alpha changes don't require a full update call

The cpp component shouldn't crash in such a case but detect the missing footprint component when trying to access it, show an error message and exit gracefully.

Furthermore the GetSchema() should be extended to require Footprint.

[Mohamed Moanis]

Can I own this ticket. I already fixed the crash and can submit a patch for review. I just have 1 question about the change in the schema; do you mean the schema in the CCmpSelectable class, should contain require Footprint?

[elexis]

Yes, because Selectable means showing a selection ring and that is scaled according to the footprint

[elexis]

Actually nevermind what I said. We can't require other components.

[Mohamed Moanis]

The problem can't be reproduced on master-branch. It appears to be solved indirectly by #4349 (​https://code.wildfiregames.com/D238)

[Itms]

Even if the crash disappeared, it would be great to have your patch! You can take a look at SubmittingPatches.

You could even look into adding a unit test so we make sure we don't stumble into the issue again :)

[elexis]

There is only one reference to m_BuildingOverlay in this file and that has a check for initialization added with the commit mentioned above: ​https://code.wildfiregames.com/rP19519#inline-398

But a unit test could be written that just creates such a component without creating a footprint component and tests whether it crashes or not.

Such a fle would have to be added to source/simulation2/components/tests/test_Selectable.h.

[Imarok]

Move tickets to Simulation as UI & Simulation got some sub components.