Don't return error if directory doesn't exist yet

services/clsi/app/coffee/OutputFileFinder.coffee

@@ -47,9 +47,8 @@ module.exports = OutputFileFinder =
 		proc.on "error", callback	
 		proc.on "close", (code) ->
 			if code != 0
-				error = new Error("find returned non-zero exit code: #{code}")
+				logger.warn {directory, code}, "find returned error, directory likely doesn't exist"
-				return callback(error)
+				return callback null, []
-			
 			fileList = stdout.trim().split("\n")
 			fileList = fileList.map (file) ->
 				# Strip leading directory

services/clsi/test/unit/coffee/OutputFileFinderTests.coffee

@@ -11,7 +11,7 @@ describe "OutputFileFinder", ->
 		@OutputFileFinder = SandboxedModule.require modulePath, requires:
 			"fs": @fs = {}
 			"child_process": spawn: @spawn = sinon.stub()
-			"logger-sharelatex": { log: sinon.stub() }
+			"logger-sharelatex": { log: sinon.stub(), warn: sinon.stub() }
 		@directory = "/test/dir"
 		@callback = sinon.stub()
 
@@ -43,6 +43,8 @@ describe "OutputFileFinder", ->
 			@directory = "/base/dir"
 			@OutputFileFinder._getAllFiles @directory, @callback
 			
+		describe "successfully", ->
+			beforeEach ->
 				@proc.stdout.emit(
 					"data",
 					["/base/dir/main.tex", "/base/dir/chapters/chapter1.tex"].join("\n") + "\n"
@@ -55,3 +57,12 @@ describe "OutputFileFinder", ->
 					["main.tex", "chapters/chapter1.tex"]
 				).should.equal true
 
+		describe "when the directory doesn't exist", ->
+			beforeEach ->
+				@proc.emit "close", 1
+				
+			it "should call the callback with a blank array", ->
+				@callback.calledWith(
+					null,
+					[]
+				).should.equal true