patch 8.2.2320: Vim9: no error for comparing bool with string

Problem:    Vim9: no error for comparing bool with string.
Solution:   Check for wrong types when comparing. (closes #7639)

src/errors.h

@@ -341,3 +341,5 @@ 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"));

src/testdir/test_vim9_expr.vim

@@ -597,6 +597,18 @@ def Test_expr4_equal()
   CheckDefFailure(["var x = 'a' == "], 'E1097:', 3)
 
   CheckDefExecFailure(['var items: any', 'eval 1', 'eval 2', 'if items == []', 'endif'], 'E691:', 4)
+
+  CheckDefExecFailure(['var x: any = "a"', 'echo x == true'], 'E1072: Cannot compare string with bool', 2)
+  CheckDefExecFailure(["var x: any = true", 'echo x == ""'], 'E1072: Cannot compare bool with string', 2)
+  CheckDefExecFailure(["var x: any = 99", 'echo x == true'], 'E1138', 2)
+  CheckDefExecFailure(["var x: any = 'a'", 'echo x == 99'], 'E1030:', 2)
+
+  for op in ['>', '>=', '<', '<=', '=~', '!~']
+    CheckDefExecFailure([
+        "var a: any = 'a'",
+        'var b: any = true',
+        'echo a ' .. op .. ' b'], 'E1072:', 3)
+  endfor
 enddef
 
 " test != comperator

src/typval.c

@@ -834,6 +834,30 @@ typval_compare(
 	    default:  break;  // avoid gcc warning
 	}
     }
+    else if (in_vim9script() && (typ1->v_type == VAR_BOOL
+						 || typ2->v_type == VAR_BOOL))
+    {
+	if (typ1->v_type != typ2->v_type)
+	{
+	    semsg(_(e_cannot_compare_str_with_str),
+		       vartype_name(typ1->v_type), vartype_name(typ2->v_type));
+	    clear_tv(typ1);
+	    return FAIL;
+	}
+	n1 = typ1->vval.v_number;
+	n2 = typ2->vval.v_number;
+	switch (type)
+	{
+	    case EXPR_IS:
+	    case EXPR_EQUAL:    n1 = (n1 == n2); break;
+	    case EXPR_ISNOT:
+	    case EXPR_NEQUAL:   n1 = (n1 != n2); break;
+	    default:
+		emsg(_(e_invalid_operation_for_bool));
+		clear_tv(typ1);
+		return FAIL;
+	}
+    }
     else
     {
 	s1 = tv_get_string_buf(typ1, buf1);

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2320,
 /**/
     2319,
 /**/