Fix HTML validator menu

The W3C validator is now protected under a CloudFlare JavaScript
challenge. However, it can be bypassed by opening directly the link
after the redirection. It doesn't work if an HTML 5 page is loaded, as
that would redirect to the Nu validator which will attempt to run the
challenge again.

So the current solution is to use the "legacy" W3C validator for HTML
4.01 or older documents and the W3C Nu validator for HTML 5 documents
only. Users would need to choose which one to use manually (at least for
now).

The WDG validator at https://www.htmlhelp.org/tools/validator/ is gone,
the server reports "Server unable to read htaccess file, denying access
to be safe", so it has been removed.

Fixes: https://github.com/dillo-browser/dillo/issues/113

2 files changed, 21 insertions, 10 deletions

diff --git a/ChangeLog b/ChangeLog
index d1cdef3a..bc40b79d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -62,6 +62,7 @@ dillo-3.1 [not released yet]
  - Enable Doxygen for C files and use Awesome Doxygen theme.
  - Fix DPIs extension (.dpi.exe) in Windows systems via Cygwin.
  - Add support for the <main> HTML tag.
+ - Fix W3C validator and remove broken WDG validator.
    Patches: Rodrigo Arias Mallo <rodarima@gmail.com>
 
 -----------------------------------------------------------------------------
diff --git a/src/menu.cc b/src/menu.cc
index 9bdf6999..a1252989 100644
--- a/src/menu.cc
+++ b/src/menu.cc
@@ -2,6 +2,7 @@
  * File: menu.cc
  *
  * Copyright (C) 2005-2007 Jorge Arellano Cid <jcid@dillo.org>
+ * Copyright (C) 2024 Rodrigo Arias Mallo <rodarima@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -255,20 +256,27 @@ static void Menu_bugmeter_validate(const char *validator_url)
 }
 
 /**
- * Validate URL with the W3C
+ * Validate URL with the W3C Nu validator (for HTML 5)
  */
-static void Menu_bugmeter_validate_w3c_cb(Fl_Widget*, void*)
+static void Menu_bugmeter_validate_w3c_nu_cb(Fl_Widget*, void*)
 {
-   Menu_bugmeter_validate("http://validator.w3.org/check?uri=%s");
+   Menu_bugmeter_validate(
+         "https://validator.w3.org/nu/"
+         "?useragent=Validator.nu%%2FLV+https%%3A%%2F%%2Fvalidator.w3.org%%2Fservices"
+         "&acceptlanguage="
+         "&doc=%s");
 }
 
 /**
- * Validate URL with the WDG
+ * Validate URL with the W3C legacy validator (HTML 4.01 and older)
  */
-static void Menu_bugmeter_validate_wdg_cb(Fl_Widget*, void*)
+static void Menu_bugmeter_validate_w3c_cb(Fl_Widget*, void*)
 {
    Menu_bugmeter_validate(
-      "http://www.htmlhelp.org/cgi-bin/validate.cgi?url=%s&warnings=yes");
+         "https://validator.w3.org/check?uri=%s"
+         "&charset=%%28detect+automatically%%29"
+         "&doctype=Inline&group=0"
+         "&user-agent=W3C_Validator%%2F1.3+");
 }
 
 /**
@@ -584,10 +592,12 @@ void a_Menu_file_popup(BrowserWindow *bw, void *v_wid)
 void a_Menu_bugmeter_popup(BrowserWindow *bw, const DilloUrl *url)
 {
    static Fl_Menu_Item pm[] = {
-      {"Validate URL with W3C", 0, Menu_bugmeter_validate_w3c_cb,0,0,0,0,0,0},
-      {"Validate URL with WDG", 0, Menu_bugmeter_validate_wdg_cb, 0,
-       FL_MENU_DIVIDER,0,0,0,0},
-      {"About bug meter", 0, Menu_bugmeter_about_cb,0,0,0,0,0,0},
+      {"Validate URL with W3C Nu validator (HTML5 only)", 0,
+         Menu_bugmeter_validate_w3c_nu_cb,0,0,0,0,0,0},
+      {"Validate URL with W3C validator (HTML 4.01 and older)", 0,
+         Menu_bugmeter_validate_w3c_cb,0,FL_MENU_DIVIDER,0,0,0,0},
+      {"About bug meter", 0,
+         Menu_bugmeter_about_cb,0,0,0,0,0,0},
       {0,0,0,0,0,0,0,0,0}
    };