clone project plow though null doc/file/folders

https://sentry.io/sharelatex-1/sl-web-server-prod/issues/227107799/

services/web/app/coffee/Features/Project/ProjectDuplicator.coffee

@@ -15,9 +15,11 @@ module.exports = ProjectDuplicator =
 	_copyDocs: (newProject, originalRootDoc, originalFolder, desFolder, docContents, callback)->
 		setRootDoc = _.once (doc_id)->
 			projectEntityHandler.setRootDoc newProject._id, doc_id
-
-		jobs = originalFolder.docs.map (doc)->
+		docs = originalFolder.docs or []
+		jobs = docs.map (doc)->
 			return (cb)->
+				if !doc?._id?
+					return callback()
 				content = docContents[doc._id.toString()]
 				projectEntityHandler.addDocWithProject newProject, desFolder._id, doc.name, content.lines, (err, newDoc)->
 					if err?
@@ -30,7 +32,8 @@ module.exports = ProjectDuplicator =
 		async.series jobs, callback
 
 	_copyFiles: (newProject, originalProject_id, originalFolder, desFolder, callback)->
-		jobs = originalFolder.fileRefs.map (file)->
+		fileRefs = originalFolder.fileRefs or []
+		jobs = fileRefs.map (file)->
 			return (cb)->
 				projectEntityHandler.copyFileFromExistingProjectWithProject newProject, desFolder._id, originalProject_id, file, cb
 		async.parallelLimit jobs, 5, callback
@@ -40,10 +43,14 @@ module.exports = ProjectDuplicator =
 		ProjectGetter.getProject newProject_id, {rootFolder:true, name:true}, (err, newProject)->
 			if err?
 				logger.err project_id:newProject_id, "could not get project"
-				return cb(err)
+				return callback(err)
+
+			folders = originalFolder.folders or []
 
-			jobs = originalFolder.folders.map (childFolder)->
+			jobs = folders.map (childFolder)->
 				return (cb)->
+					if !childFolder?._id?
+						return cb()
 					projectEntityHandler.addFolderWithProject newProject, desFolder?._id, childFolder.name, (err, newFolder)->
 						return cb(err) if err?
 						ProjectDuplicator._copyFolderRecursivly newProject_id, originalProject_id, originalRootDoc, childFolder, newFolder, docContents, cb

services/web/test/UnitTests/coffee/Project/ProjectDuplicatorTests.coffee

@@ -9,7 +9,7 @@ describe 'ProjectDuplicator', ->
 		@level2folder =
 			name: "level2folderName"
 			_id:"level2folderId"
-			docs:[@doc2 = {_id: "doc2_id", name:"level2folderDocName"}]
+			docs:[@doc2 = {_id: "doc2_id", name:"level2folderDocName"}, undefined]
 			folders:[]
 			fileRefs:[{name:"file2", _id:"file2"}]
 		@level1folder =
@@ -17,12 +17,12 @@ describe 'ProjectDuplicator', ->
 			_id:"level1folderId"
 			docs:[@doc1 = {_id: "doc1_id", name:"level1folderDocName"}]
 			folders:[@level2folder]
-			fileRefs:[{name:"file1", _id:"file1"}]
+			fileRefs:[{name:"file1", _id:"file1"}, null]
 		@rootFolder = 
 			name:"rootFolder"
 			_id:"rootFolderId"
 			docs:[@doc0 = {_id: "doc0_id", name:"rootDocHere"}]
-			folders:[@level1folder]
+			folders:[@level1folder, {}]
 			fileRefs:[{name:"file0", _id:"file0"}]
 		@project = 
 			_id: @old_project_id = "this_is_the_old_project_id"
@@ -117,7 +117,7 @@ describe 'ProjectDuplicator', ->
 			@projectOptionsHandler.setCompiler.calledWith(@stubbedNewProject._id, @project.compiler).should.equal true
 			done()
 	
-	it 'should use the same root docccccccc', (done)->
+	it 'should use the same root doc', (done)->
 		@entityHandler.addDocWithProject.callsArgWith(4, null, @rootFolder.docs[0])
 		@duplicator.duplicate @owner, @old_project_id, "", (err, newProject)=>
 			@entityHandler.setRootDoc.calledWith(@stubbedNewProject._id, @rootFolder.docs[0]._id).should.equal true