vim-patch:8.1.1828: not strict enough checking syntax of method invocation

Problem:    Not strict enough checking syntax of method invocation.
Solution:   Check there is no white space inside ->method(.
5184132ec0

runtime/doc/eval.txt

@@ -1053,12 +1053,19 @@ For methods that are also available as global functions this is the same as: >
 	name(expr8 [, args])
 There can also be methods specifically for the type of "expr8".
 
-"->name(" must not contain white space.  There can be white space before "->"
+This allows for chaining, passing the value that one method returns to the
-and after the "(".
+next method: >
-
-This allows for chaining, using the type that the method returns: >
 	mylist->filter(filterexpr)->map(mapexpr)->sort()->join()
 <
+							*E274*
+"->name(" must not contain white space.  There can be white space before the
+"->" and after the "(", thus you can split the lines like this: >
+	mylist
+	\ ->filter(filterexpr)
+	\ ->map(mapexpr)
+	\ ->sort()
+	\ ->join()
+<
 
 							*expr9*
 number

src/nvim/eval.c

@@ -4134,6 +4134,11 @@ static int eval_method(char_u **const arg, typval_T *const rettv,
         EMSG2(_(e_missingparen), name);
       }
       ret = FAIL;
+    } else if (ascii_iswhite((*arg)[-1])) {
+      if (verbose) {
+        EMSG(_("E274: No white space allowed before parenthesis"));
+      }
+      ret = FAIL;
     } else {
       ret = eval_func(arg, name, len, rettv, evaluate, &base);
     }

src/nvim/testdir/test_method.vim

@@ -118,4 +118,14 @@ func Test_method_funcref()
   delfunc Concat
 endfunc
 
+func Test_method_syntax()
+  eval [1, 2, 3]  ->sort( )
+  eval [1, 2, 3]  
+	\ ->sort(
+	\ )
+  call assert_fails('eval [1, 2, 3]-> sort()', 'E260:')
+  call assert_fails('eval [1, 2, 3]->sort ()', 'E274:')
+  call assert_fails('eval [1, 2, 3]-> sort ()', 'E260:')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab