Fixing Bugs on Issues 6 and 11

[maurodelossantos]

The two following bugs were fixed:

1. Dead Symlink Handling

Description

When serving the dir / and trying to navigate to other folders, i.e. /etc/, the request made was to /tc.

Problem

The function get_relative_path in utils/path.py worked fine for every served directory because the function os.path.abspath, used multiple times within the code, removed any ending / character. The problem came when the served directory was /. This was the only case where a folder contained a finishing slash / causing a bug in how the path was interpreted.

Solution

Substitute the previous logic to get a relative path using now the os.path.relpath() function, and manually handling the edge case of / being served with a special if statement to convert it to the empty string ''.

2. Serving "/" leads to miss the first letter of directory

Description

Web server crashes if it's asked to list a directory containing a dead symlink.

Problem

The function process_files calls the function file.is_dir(). When the variable file is a dead symlink, this raises an exception which is not handled and makes Updog crash.

Solution

Add an extra check before the line file.is_dir() where we validate that the file exists, using the os.path.exists() function.