Downloading file in dm repository without file displays blank screen

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X, Master
• Fix Version/s: 7.0.X, 7.1.0 Beta 3, 7.1.X, Master
• Component/s: Document Repository Framework
• Labels:
  • QA-V
  • profiq
• Branch Version/s:
  7.0.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/59215
• Bug Type: Regression Bug

When user tries to download Document without file, it's redirects to blank screen.

Steps:

1. Create Repository (Alfresco) in D&M of site
2. Create document in D&M root without file (e.g. Contract)
3. Move document to Repository
4. Access folder with moved document in Repository
5. Select documents kebab menu > Download

Actual result: Blank screen, no file produced, error in Liferay server log (see attached gif)
Expected: File with 0 size produced OR error message in Liferay instance in browser

Works correctly:
Server: CentOS, MySQL 5.6, Liferay 7.0.5 GA 6
Client: Firefox ESR, Chrome 66 (both Linux 64bit)

Failed:
Server: CentOS, MySQL 5.6, Liferay master git id: e608b67c9d2b84f40721bf28f036d4186f81a520
Client: Firefox ESR, Chrome 66 (both Linux 64bit)

Fix priority: L2 + S3 = 3