Fix #891 - Do not check ctrlp-funky windows

autoload/ale.vim

@@ -48,6 +48,7 @@ function! ale#ShouldDoNothing(buffer) abort
     \   || ale#util#InSandbox()
     \   || !ale#Var(a:buffer, 'enabled')
     \   || ale#FileTooLarge()
+    \   || getbufvar(a:buffer, '&l:statusline') =~# 'CtrlPMode.*funky'
 endfunction
 
 " (delay, [linting_flag, buffer_number])

test/test_should_do_nothing_conditions.vader

@@ -0,0 +1,12 @@
+Before:
+  Save &l:statusline
+
+After:
+  Restore
+
+Execute(ALE shouldn't do much of anything for ctrlp-funky buffers):
+  Assert !ale#ShouldDoNothing(bufnr('')), 'The preliminary check failed'
+
+  let &l:statusline = '%#CtrlPMode2# prt %*%#CtrlPMode1# line %* <mru>={%#CtrlPMode1# funky %*}=<fil> <-> %=%<%#CtrlPMode2# %{getcwd()} %*'
+
+  Assert ale#ShouldDoNothing(bufnr(''))