LXQtCustomCommand: trim command to remove spaces

[gfgit]

This fixes crash when command is made of only whitespace characters. It's not detected as empty and upon argument split, it tries to access first element of an empty list.

Also trim when saving settings in LXQtCustomCommandConfiguration so placeholder text shows up on next run.

The crash happens for assert failure called from either runCommand() or runDetached()

LXQtCustomCommandConfiguration slots have QString passed by value, this could be optimized with pass by const reference.

[stefonarch]

Can confirm that this fixes the issue, nice catch!

[tsujan]

Thanks!

It's good to use QString::trimmed(), but now that you're at it, would you please also remove the redundant version checks from LXQtCustomCommand::runCommand and LXQtCustomCommand::runDetached? — the required version of Qt is already 5.15.0 in the main cmake file.

[gfgit]

Ok. What about pass by value thing?
Also why runCommand does not run detached?

[tsujan]

Also why runCommand does not run detached?

A good question, indeed. Would you also investigate that? I haven't read that code for ages.

EDIT: It needs to be attached; see my next comment.

[tsujan]

Oh, the answer is LXQtCustomCommand::handleFinished.

[tsujan]

GTM.

I'm merging it for not having unrelated changes in the same commit.