Go back to using WebKit-provided user agent

As of midori-browser#49 the user agent was hard-coded in an effort to reduce
fingerprinting. Unfortunately this breaks websites such as
YouTube which incorrectly sniff for features.
The Midori version can remain decoupled.

Fixes: midori-browser#160

CMakeLists.txt

@@ -68,9 +68,7 @@ set(CFLAGS "${CFLAGS} -g")
 set(VALA_CFLAGS "-g -fPIC -w -Werror")
 
 set(LIBCORE "${CMAKE_PROJECT_NAME}-core")
-set(CORE_OS "(X11; Linux x86_64)")
-set(CORE_ENGINE "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36")
-set(CORE_USER_AGENT "Mozilla/5.0 ${CORE_OS} ${CORE_ENGINE} Midori/6")
+set(CORE_USER_AGENT_VERSION "Midori/6")
 
 configure_file(config.h.in config.h @ONLY)
 

config.h.in

@@ -10,7 +10,7 @@
 */
 
 #cmakedefine CORE_VERSION "@CORE_VERSION@"
-#cmakedefine CORE_USER_AGENT "@CORE_USER_AGENT@"
+#cmakedefine CORE_USER_AGENT_VERSION "@CORE_USER_AGENT_VERSION@"
 #cmakedefine PROJECT_NAME "@CMAKE_PROJECT_NAME@"
 #cmakedefine PROJECT_BUGS "@PROJECT_BUGS@"
 #cmakedefine PROJECT_WEBSITE "@PROJECT_WEBSITE@"

core/tab.vala

@@ -60,7 +60,7 @@ namespace Midori {
             Object (related_view: related, web_context: web_context, visible: true);
 
             var settings = get_settings ();
-            settings.user_agent = Config.CORE_USER_AGENT;
+            settings.user_agent += " %s".printf (Config.CORE_USER_AGENT_VERSION);
             settings.enable_developer_extras = true;
             var core_settings = CoreSettings.get_default ();
             settings.enable_javascript = core_settings.enable_javascript;

vapi/config.vapi

@@ -1,7 +1,7 @@
 [CCode (cprefix = "", lower_case_cprefix = "", cheader_filename = "config.h")]
 namespace Config {
     public const string CORE_VERSION;
-    public const string CORE_USER_AGENT;
+    public const string CORE_USER_AGENT_VERSION;
     public const string PROJECT_NAME;
     public const string PROJECT_BUGS;
     public const string PROJECT_WEBSITE;