From 9d6bd9a52d4caa1539330aa2e6e2d185f99158ad Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sun, 22 Oct 2017 00:35:29 +0200
Subject: [PATCH] Fix webkit_web_view_run_javascript() callback signature

Don't use wrong types and then cast the function pointer to the right
type, but just use the correct type from the beginning.

Also make the callback extern "C", as it should be, to be called from C
code.
---
 src/gtk/webview_webkit2.cpp | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/gtk/webview_webkit2.cpp b/src/gtk/webview_webkit2.cpp
index 59fa602c63..ff5076fffc 100644
--- a/src/gtk/webview_webkit2.cpp
+++ b/src/gtk/webview_webkit2.cpp
@@ -1099,17 +1099,21 @@ wxString wxWebViewWebKit::GetPageText() const
     return wxString();
 }
 
-static void wxgtk_run_javascript_cb(WebKitWebView *,
-                                    GAsyncResult *res,
-                                    GAsyncResult **res_out)
+extern "C"
+{
+
+static void wxgtk_run_javascript_cb(GObject *,
+                                    GAsyncResult *res,
+                                    void *user_data)
 {
-    // Ensure that it doesn't get freed by the time we use it in
-    // RunScriptSync() itself.
     g_object_ref(res);
 
+    GAsyncResult** res_out = static_cast<GAsyncResult**>(user_data);
     *res_out = res;
 }
 
+} // extern "C"
+
 // Run the given script synchronously and return its result in output.
 bool wxWebViewWebKit::RunScriptSync(const wxString& javascript, wxString* output)
 {
@@ -1117,7 +1121,7 @@ bool wxWebViewWebKit::RunScriptSync(const wxString& javascript, wxString* output
     webkit_web_view_run_javascript(m_web_view,
                                    javascript,
                                    NULL,
-                                   (GAsyncReadyCallback)wxgtk_run_javascript_cb,
+                                   wxgtk_run_javascript_cb,
                                    &result);
 
     GMainContext *main_context = g_main_context_get_thread_default();