inputcapture: Assert that we don't receive Response signals after dispose

When the Call object is disposed, it unsubscribes from the Response
signal before releasing its GTask reference, so it should be impossible
to get into the Response handler after dispose. Clarify that.

Signed-off-by: Simon McVittie <smcv@debian.org>

Author: smcv

libportal/inputcapture.c

@@ -544,6 +544,10 @@ get_zones_done (GDBusConnection *bus,
   guint32 response;
   g_autoptr(GVariant) ret = NULL;
 
+  /* If the Call has already been disposed, we should have unsubscribed
+   * from the Response signal at that time, so we shouldn't get here */
+  g_return_if_fail (G_IS_TASK (call->task));
+
   g_variant_get (parameters, "(u@a{sv})", &response, &ret);
 
   if (response != 0)
@@ -677,6 +681,10 @@ session_created (GDBusConnection *bus,
   guint32 response;
   g_autoptr(GVariant) ret = NULL;
 
+  /* If the Call has already been disposed, we should have unsubscribed
+   * from the Response signal at that time, so we shouldn't get here */
+  g_return_if_fail (G_IS_TASK (call->task));
+
   g_variant_get (parameters, "(u@a{sv})", &response, &ret);
 
   if (response != 0)
@@ -956,6 +964,10 @@ set_pointer_barriers_done (GDBusConnection *bus,
   GVariant *failed = NULL;
   GList *failed_list = NULL;
 
+  /* If the Call has already been disposed, we should have unsubscribed
+   * from the Response signal at that time, so we shouldn't get here */
+  g_return_if_fail (G_IS_TASK (call->task));
+
   g_variant_get (parameters, "(u@a{sv})", &response, &ret);
 
   if (g_variant_lookup (ret, "failed_barriers", "@au", &failed))