Add shim xdg-email implementation

As many 3rd party applications rely on xdg-utils for interacting
with the desktop environment, it makes sense for runtimes to provide
the expected tools. However there's no good reason to ship the usual
shell scripts, as the desktop abstraction is already provided by the
portal layer when running in a sandbox. Just add a small command line
tool that directly calls out to the portal.

src/Makefile.am

@@ -1,6 +1,12 @@
-bin_PROGRAMS = xdg-open
+bin_PROGRAMS = xdg-open xdg-email
 
 xdg_open_SOURCES = xdg-open.c
 
 xdg_open_CFLAGS = $(FLATPAK_XDG_UTILS_CFLAGS)
 xdg_open_LDADD  = $(FLATPAK_XDG_UTILS_LIBS)
+
+
+xdg_email_SOURCES = xdg-email.c
+
+xdg_email_CFLAGS = $(FLATPAK_XDG_UTILS_CFLAGS)
+xdg_email_LDADD  = $(FLATPAK_XDG_UTILS_LIBS)

src/xdg-email.c

@@ -0,0 +1,176 @@
+/*
+ * Copyright © 2017 Red Hat, Inc
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *       Florian Müllner <[email protected]>
+ */
+
+#include <gio/gio.h>
+
+#include <glib/gi18n.h>
+
+#define PORTAL_BUS_NAME    "org.freedesktop.portal.Desktop"
+#define PORTAL_OBJECT_PATH "/org/freedesktop/portal/desktop"
+#define PORTAL_IFACE_NAME  "org.freedesktop.portal.Email"
+
+static char **uris = NULL;
+static gboolean show_help = FALSE;
+static gboolean show_version = FALSE;
+
+static gboolean use_utf8 = FALSE;
+static char *subject = NULL;
+static char *body = NULL;
+static char *attach = NULL;
+
+static gboolean
+warn_ignored_parameter (const char  *option_name,
+                        const char  *value,
+                        gpointer     data,
+                        GError     **error);
+
+static GOptionEntry entries[] = {
+  {"utf8", 0, 0, G_OPTION_ARG_NONE, &use_utf8,
+   N_("Indicates that all command line options are in utf8"), NULL },
+  { "cc", 0, 0, G_OPTION_ARG_CALLBACK, warn_ignored_parameter,
+    N_("Specify a recipient to be copied on the e-mail"), N_("address")},
+  { "bcc", 0, 0, G_OPTION_ARG_CALLBACK, warn_ignored_parameter,
+    N_("Specify a recipient to be blindly copied on the e-mail"), N_("address")},
+  { "subject", 0, 0, G_OPTION_ARG_STRING, &subject,
+    N_("Specify a subject for the e-mail"), N_("text")},
+  { "body", 0, 0, G_OPTION_ARG_STRING, &body,
+    N_("Specify a body for the e-mail"), N_("text")},
+  { "attach", 0, 0, G_OPTION_ARG_FILENAME, &attach,
+    N_("Specify an attachment for the e-mail"), N_("file")},
+
+  /* Compat options with "real" xdg-open */
+  { "manual", 0, G_OPTION_FLAG_HIDDEN, G_OPTION_ARG_NONE, &show_help, NULL, NULL },
+  { "version", 0, 0, G_OPTION_ARG_NONE, &show_version, N_("Show program version"), NULL },
+
+  { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &uris, NULL, NULL }
+};
+
+static gboolean
+warn_ignored_parameter (const char  *option_name,
+                        const char  *value,
+                        gpointer     data,
+                        GError     **error)
+{
+  g_printerr ("Option %s is not supported, ignoring value \"%s\"\n",
+              option_name, value);
+  return TRUE;
+}
+
+int
+main (int argc, char *argv[])
+{
+  GOptionContext *context;
+  GError *error = NULL;
+  GDBusConnection *connection;
+  GVariantBuilder opt_builder;
+
+  context = g_option_context_new ("[ mailto-uri | address(es) ]");
+
+  g_option_context_add_main_entries (context, entries, NULL);
+  g_option_context_parse (context, &argc, &argv, &error);
+
+  if (error != NULL)
+    {
+      g_printerr ("Error parsing commandline options: %s\n", error->message);
+      g_printerr ("\n");
+      g_printerr ("Try \"%s --help\" for more information.\n", g_get_prgname ());
+
+      g_error_free (error);
+      return 1;
+    }
+
+  if (show_version)
+    {
+      g_print ("%s\n", PACKAGE_VERSION);
+
+      return 0;
+    }
+
+  if (show_help || uris == NULL || g_strv_length (uris) > 1)
+    {
+      char *help = g_option_context_get_help (context, TRUE, NULL);
+      g_print ("%s\n", help);
+
+      g_free (help);
+      return 0;
+    }
+
+  connection = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);
+
+  if (connection == NULL)
+    {
+      if (error)
+        g_printerr ("Failed to connect to session bus: %s", error->message);
+      else
+        g_printerr ("Failed to connect to session bus");
+
+      g_clear_pointer (&error, g_error_free);
+      return 3;
+    }
+
+  g_variant_builder_init (&opt_builder, G_VARIANT_TYPE_VARDICT);
+
+  g_variant_builder_add (&opt_builder,
+                         "{sv}",
+                         "address", g_variant_new_string (*uris));
+
+  if (subject != NULL)
+    g_variant_builder_add (&opt_builder,
+                           "{sv}",
+                           "subject", g_variant_new_string (subject));
+
+  if (body != NULL)
+    g_variant_builder_add (&opt_builder,
+                           "{sv}",
+                           "body", g_variant_new_string (body));
+
+  if (attach != NULL)
+    g_variant_builder_add (&opt_builder,
+                           "{sv}",
+                           "attachments", g_variant_new_parsed ("[%s]", attach));
+
+  g_dbus_connection_call_sync (connection,
+                               PORTAL_BUS_NAME,
+                               PORTAL_OBJECT_PATH,
+                               PORTAL_IFACE_NAME,
+                               "ComposeEmail",
+                               g_variant_new ("(s@a{sv})",
+                                              "",
+                                              g_variant_builder_end (&opt_builder)),
+                               NULL,
+                               G_DBUS_CALL_FLAGS_NONE,
+                               -1,
+                               NULL,
+                               &error);
+
+  if (error)
+    {
+      g_printerr ("Failed to call portal: %s\n", error->message);
+
+      g_object_unref (connection);
+      g_error_free (error);
+
+      return 4;
+    }
+
+  g_object_unref (connection);
+
+  return 0;
+}