fixed funcarg parsing. F(a,) => OK, F(a ,b) => NG

Author: ynkdir

autoload/vimlparser.vim

@@ -1225,8 +1225,17 @@ function! s:VimLParser.parse_cmd_function()
         let varnode.pos = token.pos
         let varnode.value = token.value
         call add(node.rlist, varnode)
+        " XXX: Vim doesn't skip white space before comma.  F(a ,b) => E475
+        if s:iswhite(self.reader.p(0))
+          throw s:Err(printf('unexpected token: %s', self.reader.p(0)), self.reader.getpos())
+        endif
         let token = tokenizer.get()
         if token.type == s:TOKEN_COMMA
+          " XXX: Vim allows last comma.  F(a, b, ) => OK
+          if tokenizer.peek().type == s:TOKEN_PCLOSE
+            call tokenizer.get()
+            break
+          endif
         elseif token.type == s:TOKEN_PCLOSE
           break
         else

test/test_xxx_err_funcarg_space_comma.ok

@@ -0,0 +1 @@
+vimlparser: unexpected token:  : line 1 col 13

test/test_xxx_err_funcarg_space_comma.vim

@@ -0,0 +1,2 @@
+function F(a ,b)
+endfunction

test/test_xxx_funcarg_last_comma.ok

@@ -0,0 +1,2 @@
+(function (F a))
+(function (G a))

test/test_xxx_funcarg_last_comma.vim

@@ -0,0 +1,4 @@
+function F(a,)
+endfunction
+function G(a, )
+endfunction