Request new profile picture on profile picture changed notification

session.py

@@ -457,6 +457,11 @@ class Session(YowsupApp):
 		except KeyError:
 			self.logger.debug("%s not in buddy list", number)
 
+	# Called by superclass
+	def onContactPictureChanged(self, number):
+		self.logger.debug("%s changed their profile picture", number)
+		self.buddies.requestVCard(number)
+
 	def onPresenceReceived(self, _type, name, jid, lastseen):
 		self.logger.info("Presence received: %s %s %s %s", _type, name, jid, lastseen)
 		buddy = jid.split("@")[0]

yowsupwrapper.py

@@ -549,12 +549,19 @@ class YowsupApp(object):
 	def onContactStatusChanged(self, number, status):
 		"""Called when a contacts changes their status
 
-		Args
+		Args:
 			number: (str) the number of the contact who changed their status
 			status: (str) the new status
 		"""
 		pass
 
+	def onContactPictureChanged(self, number):
+		"""Called when a contact changes their profile picture
+		Args
+			number: (str) the number of the contact who changed their picture
+		"""
+		pass
+
 	def sendEntity(self, entity):
 		"""Sends an entity down the stack (as if YowsupAppLayer called toLower)"""
 		self.stack.broadcastEvent(YowLayerEvent(YowsupAppLayer.TO_LOWER_EVENT,
@@ -666,6 +673,9 @@ class YowsupAppLayer(YowInterfaceLayer):
 					entity._from.split('@')[0],
 					entity.status
 			)
+		elif (isinstance(entity, SetPictureNotificationProtocolEntity) or
+				isinstance(entity, DeletePictureNotificationProtocolEntity)):
+			self.caller.onContactPictureChanged(entity.setJid.split('@')[0])
 
 	@ProtocolEntityCallback('message')
 	def onMessageReceived(self, entity):