[lsp-ui-flycheck] Clear overlays before calling (flycheck-buffer)

[MaskRay]

@yshui

[sebastiencs]

I see that the function flycheck-buffer clean itself the current buffer, what is the advantage of calling flycheck-clear from lsp-ui ?

[sebastiencs]

From a comment in flycheck-buffer function, it is not recommended to use flycheck-clear before flycheck-buffer:

;; Clear error list and mark all overlays for deletion.  We do not
;; delete all overlays immediately to avoid excessive re-displays and
;; flickering, if the same errors gets highlighted again after the check
;; completed.

[MaskRay]

I noted: "I investigated flycheck in August: "in lsp-after-diagnostics-hook, (flycheck-clear-errors) does not clear errors in the overlays" "but (flycheck-clear) will" not sure if it still applies"

@yshui reported that this may fix the issue of lingering diagnostic overlays

[brotzeit]

I'm trying to clean up a little. If this is still an issue please reopen.