Merge pull request #963 from SISheogorath/fix/crashPDF

Fix server crash on PDF creation

lib/response.js

@@ -341,6 +341,10 @@ function actionPDF (req, res, note) {
   var path = config.tmpPath + '/' + Date.now() + '.pdf'
   content = content.replace(/\]\(\//g, '](' + url + '/')
   markdownpdf().from.string(content).to(path, function () {
+    if (!fs.existsSync(path)) {
+      logger.error('PDF seems to not be generated as expected. File doesn\'t exist: ' + path)
+      return response.errorInternalError(res)
+    }
     var stream = fs.createReadStream(path)
     var filename = title
     // Be careful of special characters