[evolution/wip/webkit2] Crash on image download, dereferencing NULL GError

[Milan Crha <mcrha src gnome org>]

commit 9f45bc46ae50317347bc55ad3ef56cffaf9f0bf7
Author: Milan Crha <mcrha redhat com>
Date:   Mon Jun 6 13:53:46 2016 +0200

    Crash on image download, dereferencing NULL GError
    
    The 'error' variable is 'GError **', but the testing for non-NULL
    was done on 'error', not on '*error'.

 mail/e-http-request.c |   20 +++++++++++---------
 1 files changed, 11 insertions(+), 9 deletions(-)
---
diff --git a/mail/e-http-request.c b/mail/e-http-request.c
index cda9556..9e7711b 100644
--- a/mail/e-http-request.c
+++ b/mail/e-http-request.c
@@ -437,13 +437,15 @@ e_http_request_process_sync (EContentRequest *request,
                }
 
                if (cache) {
+                       GError *local_error = NULL;
+
                        cache_stream = camel_data_cache_add (
-                               cache, "http", uri_md5, error);
-                       if (error != NULL) {
+                               cache, "http", uri_md5, &local_error);
+                       if (local_error) {
                                g_warning (
                                        "Failed to create cache file for '%s': %s",
-                                       uri, (*error)->message);
-                               g_clear_error (error);
+                                       uri, local_error->message);
+                               g_clear_error (&local_error);
                        } else {
                                GOutputStream *output_stream;
 
@@ -454,17 +456,17 @@ e_http_request_process_sync (EContentRequest *request,
                                        output_stream,
                                        message->response_body->data,
                                        message->response_body->length,
-                                       NULL, cancellable, error);
+                                       NULL, cancellable, &local_error);
 
                                g_io_stream_close (cache_stream, NULL, NULL);
                                g_object_unref (cache_stream);
 
-                               if (error != NULL) {
-                                       if (!g_error_matches (*error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                               if (local_error != NULL) {
+                                       if (!g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
                                                g_warning (
                                                        "Failed to write data to cache stream: %s",
-                                                       (*error)->message);
-                                       g_clear_error (error);
+                                                       local_error->message);
+                                       g_clear_error (&local_error);
                                        g_object_unref (message);
                                        g_object_unref (temp_session);
                                        g_main_context_unref (context);