[evolution-data-server/gnome-3-38] EReminderWatcher: Catch a race condition when creating a calendar view

[Milan Crha <mcrha src gnome org>]

commit a044001c3c090e55e06905571f52730cb2f8e0c1
Author: Milan Crha <mcrha redhat com>
Date:   Tue Jan 5 15:19:42 2021 +0100

    EReminderWatcher: Catch a race condition when creating a calendar view
    
    There could happen a race condition when the calendar had been removed
    while the code had been waiting for a calendar view. This was not caught
    properly, which could lead to certain issues.

 src/calendar/libecal/CMakeLists.txt       |  1 +
 src/calendar/libecal/e-reminder-watcher.c | 19 +++++++++++++++++--
 src/calendar/libecal/libecal.pc.in        |  1 +
 3 files changed, 19 insertions(+), 2 deletions(-)
---
diff --git a/src/calendar/libecal/CMakeLists.txt b/src/calendar/libecal/CMakeLists.txt
index 58cf6fc1a..00632844a 100644
--- a/src/calendar/libecal/CMakeLists.txt
+++ b/src/calendar/libecal/CMakeLists.txt
@@ -3,6 +3,7 @@ glib_mkenums(e-cal-enumtypes e-cal-enums.h E_CAL_ENUMTYPES_H)
 add_pkgconfig_file(libecal.pc.in libecal-${CAL_API_VERSION}.pc)
 
 set(DEPENDENCIES
+       camel
        edbus-private
        edataserver
 )
diff --git a/src/calendar/libecal/e-reminder-watcher.c b/src/calendar/libecal/e-reminder-watcher.c
index c48bd4eb2..d6bbbd32f 100644
--- a/src/calendar/libecal/e-reminder-watcher.c
+++ b/src/calendar/libecal/e-reminder-watcher.c
@@ -34,6 +34,7 @@
 #include <string.h>
 #include <glib/gi18n-lib.h>
 
+#include "camel/camel.h"
 #include "libedataserver/libedataserver.h"
 
 #include "e-cal-check-timezones.h"
@@ -48,6 +49,7 @@ typedef struct _ClientData {
        EReminderWatcher *watcher; /* Just as an owner, not referenced */
        ECalClient *client;
        ECalClientView *view;
+       GCancellable *cancellable;
 } ClientData;
 
 struct _EReminderWatcherPrivate {
@@ -230,6 +232,7 @@ client_data_new (EReminderWatcher *watcher,
        cd->watcher = watcher;
        cd->client = client;
        cd->view = NULL;
+       cd->cancellable = NULL;
 
        return cd;
 }
@@ -241,6 +244,11 @@ client_data_free_view (ClientData *cd)
 
        g_return_if_fail (cd != NULL);
 
+       if (cd->cancellable) {
+               g_cancellable_cancel (cd->cancellable);
+               g_clear_object (&cd->cancellable);
+       }
+
        if (!cd->view)
                return;
 
@@ -384,7 +392,7 @@ client_data_view_created_cb (GObject *source_object,
 
        if (!e_cal_client_get_view_finish (client, result, &view, &local_error) || local_error || !view) {
                e_reminder_watcher_debug_print ("Failed to get view for %s: %s\n",
-                       e_source_get_uid (e_client_get_source (E_CLIENT (cd->client))),
+                       e_source_get_uid (e_client_get_source (E_CLIENT (client))),
                        local_error ? local_error->message : "Unknown error");
        } else {
                cd->view = view;
@@ -446,7 +454,14 @@ client_data_start_view (ClientData *cd,
                        e_source_get_uid (e_client_get_source (E_CLIENT (cd->client))),
                        query);
 
-               e_cal_client_get_view (cd->client, query, cancellable, client_data_view_created_cb, cd);
+               if (cd->cancellable) {
+                       g_cancellable_cancel (cd->cancellable);
+                       g_clear_object (&cd->cancellable);
+               }
+
+               cd->cancellable = camel_operation_new_proxy (cancellable);
+
+               e_cal_client_get_view (cd->client, query, cd->cancellable, client_data_view_created_cb, cd);
 
                g_free (query);
        }
diff --git a/src/calendar/libecal/libecal.pc.in b/src/calendar/libecal/libecal.pc.in
index a71e414f6..955ccd53d 100644
--- a/src/calendar/libecal/libecal.pc.in
+++ b/src/calendar/libecal/libecal.pc.in
@@ -10,5 +10,6 @@ Name: libecal
 Description: Client library for evolution calendars
 Version: @PROJECT_VERSION@
 Requires: libical-glib libedataserver-@API_VERSION@
+Requires.private: camel-@API_VERSION@
 Libs: -L${libdir} -lecal-@CAL_API_VERSION@
 Cflags: -I${privincludedir}