Make updating linter results slightly faster when the list is empty

1 files changed, 15 insertions, 11 deletions

diff --git a/autoload/ale/engine.vim b/autoload/ale/engine.vim
index a21eecdd..9ef3ba39 100644
--- a/autoload/ale/engine.vim
+++ b/autoload/ale/engine.vim
@@ -145,35 +145,39 @@ function! s:GatherOutput(job_id, line) abort
 endfunction
 
 function! s:HandleLoclist(linter_name, buffer, loclist) abort
-    let l:buffer_info = get(g:ale_buffer_info, a:buffer, {})
+    let l:info = get(g:ale_buffer_info, a:buffer, {})
 
-    if empty(l:buffer_info)
+    if empty(l:info)
         return
     endif
 
     " Remove this linter from the list of active linters.
     " This may have already been done when the job exits.
-    call filter(l:buffer_info.active_linter_list, 'v:val isnot# a:linter_name')
+    call filter(l:info.active_linter_list, 'v:val isnot# a:linter_name')
 
     " Make some adjustments to the loclists to fix common problems, and also
     " to set default values for loclist items.
     let l:linter_loclist = ale#engine#FixLocList(a:buffer, a:linter_name, a:loclist)
 
     " Remove previous items for this linter.
-    call filter(g:ale_buffer_info[a:buffer].loclist, 'v:val.linter_name isnot# a:linter_name')
-    " Add the new items.
-    call extend(g:ale_buffer_info[a:buffer].loclist, l:linter_loclist)
+    call filter(l:info.loclist, 'v:val.linter_name isnot# a:linter_name')
 
-    " Sort the loclist again.
-    " We need a sorted list so we can run a binary search against it
-    " for efficient lookup of the messages in the cursor handler.
-    call sort(g:ale_buffer_info[a:buffer].loclist, 'ale#util#LocItemCompare')
+    " We don't need to add items or sort the list when this list is empty.
+    if !empty(l:linter_loclist)
+        " Add the new items.
+        call extend(l:info.loclist, l:linter_loclist)
+
+        " Sort the loclist again.
+        " We need a sorted list so we can run a binary search against it
+        " for efficient lookup of the messages in the cursor handler.
+        call sort(l:info.loclist, 'ale#util#LocItemCompare')
+    endif
 
     if ale#ShouldDoNothing(a:buffer)
         return
     endif
 
-    call ale#engine#SetResults(a:buffer, g:ale_buffer_info[a:buffer].loclist)
+    call ale#engine#SetResults(a:buffer, l:info.loclist)
 endfunction
 
 function! s:HandleExit(job_id, exit_code) abort