spontaneous wrong error highlting

[Dushistov]

Sometime when I run M-x rust-compile, compilation error not highting, and it is impossible to jump to it via "C-x `"

Then I if rerun compilation via g or force rerendering via M-x compilation-mode all works fine.
It is spontaneous error, I can run M-x rust-compile 5 times before catch error like on the first screenshot. And 4 times I get right rendering, like on the second screenshot.

[Dushistov]

Quote from @npostavs

The basic problem is that rust-mode is using a multiline regexp, so it's
the same bug#25133.

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=25133

[f-fr]

I stumbled across the same bug and I use the following solution that seems to work fine (for me). The idea is as follows: The code compile.el tests for a text-property compilation-multiline (which does not seem to be used anywhere in the Emacs sources, but the code is still there). When new compilation output arrives, Emacs will start looking for error messages not at first new character but goes back as long as the previous line (actually the last character in a line) has this property set. Hence, the code below sets up a compilation-filter-hook to mark the first line of an error message as compilation-multiline:

(defun rust-multiline-error-filter ()
  (save-excursion
    (let ((start compilation-filter-start)
          (end (point)))
      (goto-char start)
      (beginning-of-line)  ; is this necessary? should not harm ...
      (while (re-search-forward "^\\(error\\|warning\\)\\(?:\\[E[0-9]+\\]\\)?:[^\n]*[\n]" end t)
        (put-text-property (match-beginning 0) (match-end 0) 'compilation-multiline t)))))
(add-hook 'rust-mode-hook
          (lambda () (add-hook 'compilation-filter-hook #'rust-multiline-error-filter)))

[gatoWololo]

I had this same problem @Lyro thank you for posting your solution!

Edit Update: Sadly I don't believe this solution makes things better, I still have these issues :(