Editor does not refresh screen when deleting near EOF

[redmunds]

This does not reproduce in Sprint 21! Both Mac and Win (with slightly different recipes). Does not seem to be any file corruption -- just a refresh problem.

1. Open a longer file such as src/styles/brackets.less
2. Ctrl-End or Cmd-down to go to end of file
3. Select from EOF up to half the screen or so
4. Press Delete or Backspace

Results:
Huge block of unpainted screen at top of editor. It doesn't really matter how much is selected, but more makes it easier to see.

Mac Details:
Seems to require the EOF is part of selection

Windows Details:
EOF does not need to be part of selection. Needs to be last page of file so the text above selection fills in the page.

[dangoor]

Gave me a good excuse to try git bisect for the first time :)

7abaf6f (a CodeMirror update) is the culprit.

[njx]

I bisected in CodeMirror—looks like this is the actual commit that broke it:
codemirror/codemirror5@5062194

He revised that patch in a later commit, but it's still broken:
codemirror/codemirror5@9338ba4

[njx]

Filed as codemirror/codemirror5#1391

[njx]

...and already fixed :) Need to decide if we want to take it for this sprint.

[njx]

Per @adrocknaphobia, moving to sprint 23.

[njx]

Marking as "for release note" - @peterflynn, can you add this to the Sprint 22 release notes? Thanks.

[peterflynn]

Just realized this only repros if you have word wrap enabled. I've updated title & steps to reflect this.

[njx]

I don't think that's true--in the bug I filed in CM, it reproduced in a non-word-wrap demo before Marijn fixed it.

[peterflynn]

Yeah, weird... I couldn't repro without word wrap before, but now I can.

[peterflynn]

I do have to delete a pretty large number of lines (at least 1/3 of the screen, sometimes closer to half 1/2) before it will repro, though.

[njx]

Yup, that was one reason why we were okay deferring it to this sprint. Marijn's fix seems to fix it--we just weren't sure about the risk.

[njx]

FBNC to @redmunds now that the latest CM is merged--wanted to bounce this back to you so you can test around various cases on Win as well. Thanks.