possible fix for exit code (#79).

autoload/airline.vim

@@ -48,19 +48,18 @@ endfunction
 
 function! airline#switch_matching_theme()
   if exists('g:colors_name')
-    let v:errmsg = ''
-    silent! let palette = g:airline#themes#{g:colors_name}#palette
-    if empty(v:errmsg)
+    try
+      let palette = g:airline#themes#{g:colors_name}#palette
       call airline#switch_theme(g:colors_name)
       return 1
-    else
+    catch
       for map in items(g:airline_theme_map)
         if match(g:colors_name, map[0]) > -1
           call airline#switch_theme(map[1])
           return 1
         endif
       endfor
-    endif
+    endtry
   endif
   return 0
 endfunction