archive files in recents extracted immediately upon startup

[brainchild0]

 * Xreader version: 2.4.4
 * Distribution: Mint 19.2

Issue

Xreader apparently writes exploded copies of all EPUB and comic book archive files in recent files list into /tmp upon startup, unless those copies already exist.

Steps to reproduce

1. Open a few large EPUB and CBZ files in Xreader.
2. Close the application.
3. Delete all directories following the shell pattern /tmp/xreader-*.
4. Open Xreader.

Expected behaviour

Xreader waits for the user to open a file.

Creation of temporary files is limited to the minimal necessary amount for a particular operation, and those files are deleted as soon as they become unneeded.

Actual behavior

Xreader scans the recent files list and writes exploded copies of all archive files to temporary files, regardless of their size and number, before opening any window, or providing any feedback to the user.

This behavior creates an enormous penalty in speed, disk usage, and usability.

[icarter09]

@brainchild0 can you post any EPUB or CBZ files to test this with? Thanks.

[brainchild0]

I can reproduce equally well using any set of EPUB documents.

I have submitted a few in the public domain.

Naturally, small documents lack the adverse affect on resources that prompted the creation of the issue, but the behavior to test is nevertheless the same in every case.

[clefebvre]

EPUB support was removed from Xreader and reimplemented in Xepub: https://github.com/xapp-project/xepub.