patch 8.2.3058: Vim9: cannot use ternary operator in parenthesis

Problem:    Vim9: cannot use ternary operator in parenthesis.
Solution:   Do not use "==" for a default argument value.  (closes #8462)

src/testdir/test_vim9_func.vim

@@ -923,6 +923,13 @@ def Test_call_lambda_args()
   END
   CheckDefAndScriptFailure(lines, 'E1172:')
 
+  lines =<< trim END
+      var a = 0
+      var b = (a == 0 ? 1 : 2)
+      assert_equal(1, b)
+  END
+  CheckDefAndScriptSuccess(lines)
+
   lines =<< trim END
       def ShadowLocal()
         var one = 1

src/userfunc.c

@@ -266,13 +266,18 @@ get_function_args(
 	}
 	else
 	{
+	    char_u *np;
+
 	    arg = p;
 	    p = one_function_arg(p, newargs, argtypes, types_optional,
 							 evalarg, FALSE, skip);
 	    if (p == arg)
 		break;
 
-	    if (*skipwhite(p) == '=' && default_args != NULL)
+	    // Recognize " = expr" but not " == expr".  A lambda can have
+	    // "(a = expr" but "(a == expr" is not a lambda.
+	    np = skipwhite(p);
+	    if (*np == '=' && np[1] != '=' && default_args != NULL)
 	    {
 		typval_T	rettv;
 

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3058,
 /**/
     3057,
 /**/