generate the message ID from an identity, and take the identity from Init() rather than from GetHackIdentity

mailnews/compose/src/nsMsgCompUtils.cpp

@@ -1054,13 +1054,15 @@ GIVE_UP_ON_CONTENT_BASE:
 }
 
 char *
-msg_generate_message_id (void)
+msg_generate_message_id (nsIMsgIdentity *identity)
 {
 	time_t now = XP_TIME();
 	PRUint32 salt = 0;
-	nsMsgCompPrefs pCompPrefs;
 	const char *host = 0;
-	const char *from = pCompPrefs.GetUserEmail();
+  
+	char *from;
+  nsresult rv = identity->GetEmail(&from);
+  if (NS_FAILED(rv)) return nsnull;
 
 	GenerateGlobalRandomBytes((unsigned char *) &salt, sizeof(salt));
 	if (from) {

mailnews/compose/src/nsMsgCompUtils.h

@@ -70,7 +70,7 @@ char        *mime_generate_attachment_headers (const char *type,
 											     nsMsgAttachmentHandler *ma,
 											     const char *charset);
 
-char        *msg_generate_message_id (void);
+char        *msg_generate_message_id (nsIMsgIdentity*);
 
 char        *RFC2231ParmFolding(const char *parmName, const char *charset, 
                       				  const char *language, const char *parmValue);

mailnews/compose/src/nsMsgSend.cpp

@@ -381,7 +381,7 @@ nsMsgComposeAndSend::GatherMimeAttachments()
   
 	if (mCompFields->GetMessageId() == nsnull || *mCompFields->GetMessageId() == 0)
 	{
-		char * msgID = msg_generate_message_id();
+		char * msgID = msg_generate_message_id(mUserIdentity);
 		mCompFields->SetMessageId(msgID, nsnull);
 		PR_FREEIF(msgID);
 	}
@@ -1200,16 +1200,9 @@ nsMsgComposeAndSend::Init(
 	m_dont_deliver_p = dont_deliver_p;
 	m_deliver_mode = mode;
 
-  //
-  // We really do need an identity, but for now, if we don't get one, just use
-  // the hack function to pass in an identity.
-  // 
-  extern nsIMsgIdentity *GetHackIdentity();
-
   mUserIdentity = aUserIdentity;
-  if (!mUserIdentity)
-    mUserIdentity = GetHackIdentity();
-
+  NS_ASSERTION(mUserIdentity, "Got null identity!\n");
+  if (!mUserIdentity) return NS_ERROR_UNEXPECTED;
 
   //
   // First sanity check the composition fields parameter and