Seemingly cleared selection after drag mode change reappears again

[rmoestl]

This is a issue discovered while implementing feature #1852 in PR #2944.

The problem: when creating a selection in lasso / select drag mode, switching to pan or zoom would clean up the visual outlines of the selection. When moving back to lasso / select without a zoom / pan operation and adding to a selection by holding Shift lets those seemingly cleared selections reappear.

#2944 has an example attached in a this comment. Please also note the TODO comments in the code.

[etpinard]

Pasting the contents of #2944 (comment) for clarity:

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Note that the go from select -> pan -> select w/o actually panning.

Personally, I wouldn't consider this a bug as the "cached" selection outlines are still "correct" (i.e. they are drawn at the correct x/y coordinates). Now, is this the "ideal" behavior, I'm not so sure.

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I like the behavior that we don't clear the selection itself until the last possible moment... but it would certainly be nice if the outline were redrawn when you switch back to a select mode. It's a sufficiently uncommon edge case though that I'd rather not hold up the PR for it - just leave it as is for now and make a new issue to follow up on this later.

[etpinard]

cc #1848

[gvwilson]

Hi - this issue has been sitting for a while, so as part of our effort to tidy up our public repositories I'm going to close it. If it's still a concern, we'd be grateful if you could open a new issue (with a short reproducible example if appropriate) so that we can add it to our stack. Cheers - @gvwilson