[gnome-software/wip/hughsie/appstream-editor] trivial: Prevent critical warning when trying to parse an invalid URI

[Richard Hughes <rhughes src gnome org>]

commit a42252892680e4a0047c8e5cdc855afd14210b10
Author: Richard Hughes <richard hughsie com>
Date:   Fri May 5 20:52:13 2017 +0100

    trivial: Prevent critical warning when trying to parse an invalid URI

 lib/gs-plugin.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/lib/gs-plugin.c b/lib/gs-plugin.c
index a8f2f04..dc29e56 100644
--- a/lib/gs-plugin.c
+++ b/lib/gs-plugin.c
@@ -1284,6 +1284,13 @@ gs_plugin_download_file (GsPlugin *plugin,
        /* remote */
        g_debug ("downloading %s to %s from plugin %s", uri, filename, priv->name);
        msg = soup_message_new (SOUP_METHOD_GET, uri);
+       if (msg == NULL) {
+               g_set_error (error,
+                            GS_PLUGIN_ERROR,
+                            GS_PLUGIN_ERROR_DOWNLOAD_FAILED,
+                            "failed to parse URI %s", uri);
+               return FALSE;
+       }
        if (app != NULL) {
                helper.plugin = plugin;
                helper.app = app;