[balsa/gtk3] Respond to bgo #770500 making webkit2 the default

[Peter Bloomfield <peterb src gnome org>]

commit 4c049a848e294b2c5747ebc31aea97db52bdeab8
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Mon Sep 5 18:35:15 2016 -0400

    Respond to bgo #770500 making webkit2 the default
    
        Respond to
        <URL:https://bugzilla.gnome.org/show_bug.cgi?id=770500>
        by making webkit2 the default instead of webkit, and warning if
        Balsa is configured for webkit.
    
        * configure.ac: make webkit2 the default HTML widget, and warn
          if Balsa is configured for webkit.

 ChangeLog    |   10 ++++++++++
 configure.ac |   12 +++++++++++-
 2 files changed, 21 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index d41f90d..8a05018 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2016-09-05  Peter Bloomfield  <pbloomfield bellsouth net>
+
+       Respond to
+       <URL:https://bugzilla.gnome.org/show_bug.cgi?id=770500>
+       by making webkit2 the default instead of webkit, and warning if
+       Balsa is configured for webkit.
+
+       * configure.ac: make webkit2 the default HTML widget, and warn
+         if Balsa is configured for webkit.
+
 2016-08-29  Peter Bloomfield  <pbloomfield bellsouth net>
 
        Plug memory leak.
diff --git a/configure.ac b/configure.ac
index 02d4861..75e538a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -112,7 +112,7 @@ AC_ARG_WITH(html-widget,
             AC_HELP_STRING([--with-html-widget=(no|gtkhtml4|webkit|webkit2)],
                            [select the HTML renderer (default webkit)]),
             [use_html_widget=$withval],
-            [use_html_widget=webkit])
+            [use_html_widget=webkit2])
 
 AC_ARG_WITH([gtksourceview],
    AC_HELP_STRING([--with-gtksourceview],
@@ -904,3 +904,13 @@ if test x"$BALSA_FROM_GIT" = xyes ; then
                   or configure --without-gnome.])
         fi
 fi
+
+if test x"$use_html_widget" = xwebkit ; then
+    AC_MSG_WARN([
+*** You have configured Balsa to use the old webkitgtk HTML widget.
+*** This widget is no longer being actively developed, and likely
+*** has security issues fixed in the newer webkit2 widget.
+*** Balsa will continue support for the old webkit widget only
+*** while needed by long-term-stable releases of major distributors.
+                 ])
+fi