fix(message-ui/edit-info): handle the case where editor can't be found

This uses a special "?" character that is understood by the /avatar/
route and will be treated specially. This change also adds url
encoding/decoding around username usage via the url for the avatar.

client/lib/avatar.coffee

@@ -8,7 +8,7 @@
 		path = Meteor.absoluteUrl()
 	else
 		path = '/'
-	return "#{path}avatar/#{username}.jpg?_dc=#{random}"
+	"#{path}avatar/#{encodeURIComponent(username)}.jpg?_dc=#{random}"
 
 Blaze.registerHelper 'avatarUrlFromUsername', getAvatarUrlFromUsername
 

client/views/app/message.coffee

@@ -54,7 +54,17 @@ Template.message.helpers
 		moment(@ets).format('LL hh:mma') #TODO profile pref for 12hr/24hr clock?
 	editedBy: ->
 		return "" unless wasEdited(@)
-		Meteor.users.findOne(@editBy ? Meteor.userId())?.username
+		# try to return the username of the editor,
+		# otherwise a special "?" character that will be
+		# rendered as a special avatar
+		if @editBy
+			user = Meteor.users.findOne(@editBy)
+			if user?
+				user.username
+			else
+				"?"
+		else
+			"?"
 	pinned: ->
 		return this.pinned
 	canEdit: ->

server/startup/avatar.coffee

@@ -30,13 +30,14 @@ Meteor.startup ->
 
 	WebApp.connectHandlers.use '/avatar/', (req, res, next) ->
 		this.params =
-			username: req.url.replace(/^\//, '').replace(/\?.*$/, '')
+			username: decodeURIComponent(req.url.replace(/^\//, '').replace(/\?.*$/, ''))
 
 		if this.params.username[0] isnt '@'
 			file = RocketChatFileAvatarInstance.getFileWithReadStream this.params.username
 		else
 			this.params.username = this.params.username.replace '@', ''
 
+		#console.log "[avatar] checking username #{@params.username} (derrived from path #{req.url})"
 		res.setHeader 'Content-Disposition', 'inline'
 
 		if not file?
@@ -45,19 +46,22 @@ Meteor.startup ->
 
 			colors = ['#F44336','#E91E63','#9C27B0','#673AB7','#3F51B5','#2196F3','#03A9F4','#00BCD4','#009688','#4CAF50','#8BC34A','#CDDC39','#FFC107','#FF9800','#FF5722','#795548','#9E9E9E','#607D8B']
 
-			username = this.params.username.replace('.jpg', '')
-			position = username.length % colors.length
-			color = colors[position]
-
-			username = username.replace(/[^A-Za-z0-9]/g, '.').replace(/\.+/g, '.').replace(/(^\.)|(\.$)/g, '')
-			usernameParts = username.split('.')
+			username = @params.username.replace('.jpg', '')
+			color = ''
 			initials = ''
-			if usernameParts.length > 1
-				initials = _.first(usernameParts)[0] + _.last(usernameParts)[0]
+			if username is "?"
+				color = "#000"
+				initials = username
 			else
-				initials = username.replace(/[^A-Za-z0-9]/g, '').substr(0, 2)
-
-			initials = initials.toUpperCase()
+				position = username.length % colors.length
+				color = colors[position]
+				username = username.replace(/[^A-Za-z0-9]/g, '.').replace(/\.+/g, '.').replace(/(^\.)|(\.$)/g, '')
+				usernameParts = username.split('.')
+				initials = if usernameParts.length > 1
+					_.first(usernameParts)[0] + _.last(usernameParts)[0]
+				else
+					username.replace(/[^A-Za-z0-9]/g, '').substr(0, 2)
+				initials = initials.toUpperCase()
 
 			svg = """
 			<?xml version="1.0" encoding="UTF-8" standalone="no"?>