[evolution] Bug 792688 - Failed mail print operation causes crash

[Milan Crha <mcrha src gnome org>]

commit b0cce4fd8fbac03050720670ff6d1033a359df55
Author: Milan Crha <mcrha redhat com>
Date:   Tue Mar 27 15:24:17 2018 +0200

    Bug 792688 - Failed mail print operation causes crash

 src/mail/e-mail-printer.c |   27 +++++++++++++++------------
 1 files changed, 15 insertions(+), 12 deletions(-)
---
diff --git a/src/mail/e-mail-printer.c b/src/mail/e-mail-printer.c
index 69a628c..f47f329 100644
--- a/src/mail/e-mail-printer.c
+++ b/src/mail/e-mail-printer.c
@@ -51,6 +51,7 @@ struct _EMailPrinterPrivate {
 struct _AsyncContext {
        WebKitWebView *web_view;
        gulong load_status_handler_id;
+       GError *error;
 
        GtkPrintOperationResult print_result;
 };
@@ -83,6 +84,7 @@ async_context_free (AsyncContext *async_context)
                        async_context->load_status_handler_id);
 
        g_clear_object (&async_context->web_view);
+       g_clear_error (&async_context->error);
 
        g_slice_free (AsyncContext, async_context);
 }
@@ -170,15 +172,22 @@ mail_printer_print_finished_cb (WebKitPrintOperation *print_operation,
 
        async_context = g_task_get_task_data (task);
        g_return_if_fail (async_context != NULL);
-       async_context->print_result = GTK_PRINT_OPERATION_RESULT_APPLY;
 
-       g_task_return_boolean (task, TRUE);
+       if (async_context->print_result == GTK_PRINT_OPERATION_RESULT_IN_PROGRESS) {
+               async_context->print_result = GTK_PRINT_OPERATION_RESULT_APPLY;
+               g_task_return_boolean (task, TRUE);
+       } else if (async_context->error) {
+               g_task_return_error (task, g_error_copy (async_context->error));
+       } else {
+               g_task_return_boolean (task, FALSE);
+       }
+
        g_object_unref (task);
 }
 
 static void
 mail_printer_print_failed_cb (WebKitPrintOperation *print_operation,
-                              GError *error,
+                              const GError *error,
                               GTask *task)
 {
        AsyncContext *async_context;
@@ -189,15 +198,7 @@ mail_printer_print_failed_cb (WebKitPrintOperation *print_operation,
        async_context = g_task_get_task_data (task);
        g_return_if_fail (async_context != NULL);
        async_context->print_result = GTK_PRINT_OPERATION_RESULT_ERROR;
-
-       if (error != NULL)
-               g_task_return_error (task, error);
-       else {
-               g_warning ("WebKit print operation returned ERROR result without setting a GError");
-               g_task_return_boolean (task, FALSE);
-       }
-
-       g_object_unref (task);
+       async_context->error = error ? g_error_copy (error) : NULL;
 }
 
 static gboolean
@@ -530,6 +531,8 @@ e_mail_printer_print (EMailPrinter *printer,
        /* EMailFormatter can be NULL. */
 
        async_context = g_slice_new0 (AsyncContext);
+       async_context->print_result = GTK_PRINT_OPERATION_RESULT_IN_PROGRESS;
+       async_context->error = NULL;
 
        part_list = e_mail_printer_ref_part_list (printer);
        folder = e_mail_part_list_get_folder (part_list);