doc: Tweak comment on behavior of VoiceCall.Hangup

diff --git a/doc/voicecall-api.txt b/doc/voicecall-api.txt
index 78960a1..2d715be 100644 (file)
--- a/doc/voicecall-api.txt
+++ b/doc/voicecall-api.txt
@@ -58,7 +58,10 @@ Methods              dict GetProperties()
 
                        NOTE: Releasing active calls does not produce
                        side-effects.  That is the state of held or waiting
-                       calls is not affected.
+                       calls is not affected.  As an exception, in the case
+                       where a single active call and a waiting call are
+                       present, releasing the active call will result in the
+                       waiting call transitioning to the 'incoming' state.
 
                        Possible Errors: [service].Error.InProgress
                                         [service].Error.Failed