patch 9.0.2116: No test for defining sign without attribute

Problem:  No test for defining sign without attribute
Solution: Add test for defining sign without attributes

closes: #13544

Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_signs.vim

@@ -194,6 +194,11 @@ func Test_sign()
   sign undefine Sign3
   call assert_fails("sign place 41 line=3 name=Sign1 buffer=" .
 			  \ bufnr('%'), 'E155:')
+
+  " Defining a sign without attributes is allowed.
+  sign define Sign1
+  call assert_equal([{'name': 'Sign1'}], sign_getdefined())
+  sign undefine Sign1
 endfunc
 
 func Test_sign_many_bytes()

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2116,
 /**/
     2115,
 /**/