invite: Deal with re-transmit of a rejected call

In case our reject does not arrive and is re-transmitted we
should reject it too.

* Modify SIPDialog>>#checkCompatible. We have to accept that
  the remote does not know the tag we assigned. Be more forgiving
* Send the INVITE again and count our rejects.

callagent/SIPDialog.st

@@ -211,7 +211,13 @@ Object subclass: SIPDialog [
         "I check if the remote and the local dialog match. I do this by cross
          checking the to/from, from/to."
         self callId = aDialog callId ifFalse: [^false].
-        self from_tag = aDialog to_tag ifFalse: [^false].
+        self from_tag = aDialog to_tag ifFalse: [
+            "In case of a re-transmission of a SIP request the remote does
+            not have our local tag yet. Deal with it by checking if we have
+            the remote tag. TODO: maybe look at the kind of request being
+            made."
+            (self isClient and: [self to_tag isNil])
+                ifTrue: [^false]].
         self to_tag = aDialog from_tag ifFalse: [^false].
 
         ^true

callagent/session/SIPIncomingCall.st

@@ -35,6 +35,7 @@ SIPCallBase subclass: SIPIncomingCall [
                 self stateInvite  -> self stateSession.
                 self stateInvite  -> self stateRejected.
                 self stateInvite  -> self stateFailed.
+                self stateRejected -> self stateRejected.
                 self stateSession -> self stateHangup.
                 self stateSession -> self stateRemoteHangup.
             }
@@ -85,5 +86,13 @@ SIPCallBase subclass: SIPIncomingCall [
                                             expandMacrosWith: dialog cseq with: 'INVITE');
                     yourself.
         ua queueData: resp asDatagram dialog: dialog.
+        self unregisterDialog.
+    ]
+
+    remoteReInvite: aRequest dialog: aDialog [
+        self state = self class stateRejected
+            ifTrue: [^self reject].
+        ^self error: ('SIPIncomingCall(<1s>) unknown action for state <2s>'
+                expandMacrosWith: self callId with: self state) area: #sip.
     ]
 ]

callagent/session/SIPSessionBase.st

@@ -75,9 +75,13 @@ a proper session.'>
         ua registerDialog: self.
     ]
 
+    unregisterDialogIsPending [
+        ^rem isNil not
+    ]
+
     unregisterDialog [
         <category: 'session'>
-        rem isNil ifTrue: [
+        rem ifNil: [
             rem := Osmo.TimerScheduler instance
                     scheduleInSeconds: 60 block: [
                         ua unregisterDialog: self.

callagent/tests/SIPInviteTest.st

@@ -73,7 +73,6 @@ TestCase subclass: SIPInviteTest [
 
         "Check the reject"
         self assert: sent size equals: 1.
-        sent first data printNl.
         msg := SIPParser parse: sent first data.
         self assert: msg code equals: '603'.
         self assert: msg phrase equals: 'Not Found'.
@@ -81,11 +80,14 @@ TestCase subclass: SIPInviteTest [
     ]
 
     testRejectCall [
-        | msg |
+        | msg call calls firstTag secondTag |
+
+        calls := 0.
 
         agent onNewCall: [:invite :dialog |
-            (SIPIncomingCall initWith: invite dialog: dialog on: agent)
-                reject].
+            calls := calls + 1.
+            call := (SIPIncomingCall initWith: invite dialog: dialog on: agent)
+                reject; yourself].
 
         "Inject the invite"
         transport inject: self createInvite.
@@ -93,10 +95,18 @@ TestCase subclass: SIPInviteTest [
         "Check the reject"
         self assert: sent size equals: 1.
         msg := SIPParser parse: sent first data.
-        sent first data printNl.
-        msg inspect.
         self assert: msg code equals: '603'.
         self assert: msg phrase equals: 'Not Found'.
         self assert: agent dialogs size equals: 1.
+        self assert: call unregisterDialogIsPending.
+        firstTag := (msg parameter: 'To' ifAbsent: []) tag.
+
+        "Do a re-transmit and see what happens.."
+        transport inject: self createInvite.
+        self assert: call unregisterDialogIsPending.
+        self assert: sent size equals: 2.
+        msg := SIPParser parse: sent second data.
+        secondTag := (msg parameter: 'To' ifAbsent: []) tag.
+        self assert: firstTag equals: secondTag.
     ]
 ]