Displaying images with spaces and colons in filename fails silently

Problem:
An image with a filename containing a colons is not shown in a ticket on Bitbucket, but can be uploaded without any problems.

Expectation
If an image uploads succesfully the image will be shown succesfully, regardless of the characters used in the filename.

Solution
URL encode all filename characters or scrub the filename in such a way that the ticket will display the image.

Details
I made a screenshot with the default application on on Ubuntu 14.04 using it's default settings. This screenshot application includes spaces and colon in the filename which looks like this: 'Screenshot from 2015-09-14 20:12:46.png' I can upload this file without any issues, but displaying the image in a ticket fails silently. See the code below which fails silently in showing a screenshot of this ticket: