patch 8.2.3176: Vim9: no type error for comparing number with string

Problem:    Vim9: no type error for comparing number with string.
Solution:   Add a runtime type check. (closes #8571)

Author: brammool

src/errors.h

@@ -381,8 +381,8 @@ EXTERN char e_mismatched_endfunction[]
 	INIT(= N_("E1151: Mismatched endfunction"));
 EXTERN char e_mismatched_enddef[]
 	INIT(= N_("E1152: Mismatched enddef"));
-EXTERN char e_invalid_operation_for_bool[]
-	INIT(= N_("E1153: Invalid operation for bool"));
+EXTERN char e_invalid_operation_for_str[]
+	INIT(= N_("E1153: Invalid operation for %s"));
 EXTERN char e_divide_by_zero[]
 	INIT(= N_("E1154: Divide by zero"));
 EXTERN char e_cannot_define_autocommands_for_all_events[]

src/testdir/test_vim9_expr.vim

@@ -660,13 +660,36 @@ def Test_expr4_equal()
   CheckDefExecAndScriptFailure(["var x: any = true", 'echo x == ""'], 'E1072: Cannot compare bool with string', 2)
   CheckDefExecAndScriptFailure2(["var x: any = 99", 'echo x == true'], 'E1138', 'E1072:', 2)
   CheckDefExecAndScriptFailure2(["var x: any = 'a'", 'echo x == 99'], 'E1030:', 'E1072:', 2)
+enddef
 
+def Test_expr4_wrong_type()
   for op in ['>', '>=', '<', '<=', '=~', '!~']
     CheckDefExecAndScriptFailure([
         "var a: any = 'a'",
         'var b: any = true',
         'echo a ' .. op .. ' b'], 'E1072:', 3)
   endfor
+  for op in ['>', '>=', '<', '<=']
+    CheckDefExecAndScriptFailure2([
+        "var n: any = 2",
+        'echo n ' .. op .. ' "3"'], 'E1030:', 'E1072:', 2)
+  endfor
+  for op in ['=~', '!~']
+    CheckDefExecAndScriptFailure([
+        "var n: any = 2",
+        'echo n ' .. op .. ' "3"'], 'E1072:', 2)
+  endfor
+
+  CheckDefAndScriptFailure([
+      'echo v:none == true'], 'E1072:', 1)
+  CheckDefAndScriptFailure([
+      'echo false >= true'], 'E1072:', 1)
+  CheckDefExecAndScriptFailure([
+      "var n: any = v:none",
+      'echo n == true'], 'E1072:', 2)
+  CheckDefExecAndScriptFailure([
+      "var n: any = v:none",
+      'echo n < true'], 'E1072:', 2)
 enddef
 
 " test != comperator

src/typval.c

@@ -937,7 +937,9 @@ typval_compare(
 	}
     }
     else if (in_vim9script() && (typ1->v_type == VAR_BOOL
-						 || typ2->v_type == VAR_BOOL))
+				    || typ2->v_type == VAR_BOOL
+				    || (typ1->v_type == VAR_SPECIAL
+					      && typ2->v_type == VAR_SPECIAL)))
     {
 	if (typ1->v_type != typ2->v_type)
 	{
@@ -955,13 +957,23 @@ typval_compare(
 	    case EXPR_ISNOT:
 	    case EXPR_NEQUAL:   n1 = (n1 != n2); break;
 	    default:
-		emsg(_(e_invalid_operation_for_bool));
+		semsg(_(e_invalid_operation_for_str),
+						   vartype_name(typ1->v_type));
 		clear_tv(typ1);
 		return FAIL;
 	}
     }
     else
     {
+	if (in_vim9script()
+	      && ((typ1->v_type != VAR_STRING && typ1->v_type != VAR_SPECIAL)
+	       || (typ2->v_type != VAR_STRING && typ2->v_type != VAR_SPECIAL)))
+	{
+	    semsg(_(e_cannot_compare_str_with_str),
+		       vartype_name(typ1->v_type), vartype_name(typ2->v_type));
+	    clear_tv(typ1);
+	    return FAIL;
+	}
 	s1 = tv_get_string_buf(typ1, buf1);
 	s2 = tv_get_string_buf(typ2, buf2);
 	if (type != EXPR_MATCH && type != EXPR_NOMATCH)

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3176,
 /**/
     3175,
 /**/