syncevolution.org binaries: fix libnotify compatibility mode (BMC #22668)

Nightly testing showed that some problems had to be fixed:
- "make dist" broken when --enable-notify-compatibility isn't set,
  because AM_CONDITIONAL() wasn't invoked.
- libnotify.so.4 wasn't opened due to an off-by-one error in the loop;
  also added some debug statements to find this.
- libnotify.so.4 binds to the specific notification daemon, so the
  method calls went to a specific bus address instead of the
  org.freedesktop.Notifications expected by test-dbus.py

configure-pre.in

@@ -523,7 +523,6 @@ if test $enable_dbus_service = "yes"; then
         AC_DEFINE(NOTIFY_COMPATIBILITY, 1, [dynamically open libnotify])
         LIBNOTIFY_LIBS="`echo $LIBNOTIFY_LIBS | sed -e 's/\(-lnotify\|[^ ]*libnotify.la\)/-ldl/'`"
     fi
-    AM_CONDITIONAL([NOTIFY_COMPATIBILITY], [test "$enable_notify_compat" = "yes"])
 
     # Here we're using QtGui too because mlite fails to depend on it,
     # despite using QAction.
@@ -543,6 +542,8 @@ if test $enable_dbus_service = "yes"; then
     fi
     AC_DEFINE(DBUS_SERVICE, 1, [define if dbus service is enabled])
 fi
+AM_CONDITIONAL([NOTIFY_COMPATIBILITY], [test "$enable_notify_compat" = "yes"])
+
 AC_SUBST(DBUS_CFLAGS)
 AC_SUBST(DBUS_LIBS)
 AC_SUBST(DBUS_GLIB_CFLAGS)

src/NotificationBackendLibnotify.cpp

@@ -85,6 +85,12 @@ void NotificationBackendLibnotify::notifyAction(
     // if dismissed, ignore.
 }
 
+static bool NotFound(const char *func)
+{
+    SE_LOG_DEBUG(NULL, NULL, "%s: not found", func);
+    return false;
+}
+
 bool NotificationBackendLibnotify::init()
 {
     bindtextdomain (GETTEXT_PACKAGE, SYNCEVOLUTION_LOCALEDIR);
@@ -93,14 +99,22 @@ bool NotificationBackendLibnotify::init()
 
 #ifdef NOTIFY_COMPATIBILITY
     void *dlhandle = NULL;
-    for (int i = 1; i < 4 && !dlhandle; i++) {
+    int i;
+    for (i = 1; i <= 4; i++) {
         dlhandle = dlopen(StringPrintf("libnotify.so.%d", i).c_str(), RTLD_LAZY|RTLD_GLOBAL);
+        if (!dlhandle) {
+            SE_LOG_DEBUG(NULL, NULL, "failed to load libnotify.so.%d: %s", i, dlerror());
+        } else {
+            break;
+        }
     }
     if (!dlhandle) {
         return false;
     }
 
-#define LOOKUP(_x) (_x = reinterpret_cast<typeof(_x)>(dlsym(dlhandle, #_x)))
+#define LOOKUP(_x) ((_x = reinterpret_cast<typeof(_x)>(dlsym(dlhandle, #_x))) || \
+                    NotFound(#_x))
+
     if (!LOOKUP(notify_init) ||
         !LOOKUP(notify_get_server_caps) ||
         !LOOKUP(notify_notification_new) ||
@@ -110,6 +124,7 @@ bool NotificationBackendLibnotify::init()
         !LOOKUP(notify_notification_show)) {
         return false;
     }
+    SE_LOG_DEBUG(NULL, NULL, "using libnotify.so.%d", i);
 #endif
 
     m_initialized = notify_init("SyncEvolution");

test/test-dbus.py

@@ -54,7 +54,7 @@ configName = "dbus_unittest"
 
 def GrepNotifications(dbuslog):
     '''finds all Notify calls and returns their parameters as list of line lists'''
-    return re.findall(r'^method call .* dest=org.freedesktop.Notifications .*interface=org.freedesktop.Notifications; member=Notify\n((?:^   .*\n)*)',
+    return re.findall(r'^method call .* dest=.* .*interface=org.freedesktop.Notifications; member=Notify\n((?:^   .*\n)*)',
                       dbuslog,
                       re.MULTILINE)