No message is shown to the frontend user when an corrupted pdf file is stored in the repository

1. Log-in to CMS
2. Navigate to assests & upload the attached corrupted pdf file

Expected - Frontend user should get an indication somewhere that pdf file is corrupted
Actual - No message is shown except the below in terminal

[INFO] [talledLocalContainer] 28.09.2012 15:08:41 WARN [org.apache.pdfbox.pdfparser.BaseParser.parseCOSDictionary():279] Invalid dictionary, found: '?' but expected: '/'
[INFO] [talledLocalContainer] 28.09.2012 15:08:41 WARN [org.apache.pdfbox.pdfparser.XrefTrailerResolver.setStartxref():165] Did not found XRef object at specified startxref position 0