.epub file opens with browser instead books app, starts unstoppable attempts to download something

REPRODUCIBILITY (% or how often): 100%
BUILD ID = OS VERSION (Settings > About product): 4.1.0.24 Geräte Adaption 0.0.5.14
HARDWARE (XA2, X10, X10 II, …): Xperia 10 Dual SIM
UI LANGUAGE: German
REGRESSION: (compared to previous public release: Yes, No, ?): ???

DESCRIPTION:

.epub files don´t open with Books app if tapped in File Browser, but do open internet browser and start some download.

PRECONDITIONS:

Copied a book (.epub file) to the phone and wanted to check if I catched the correct version with images. Source of the .epub file is bücherbucht.de , so copyright protection should be no problem.

STEPS TO REPRODUCE:

  1. Copy .epub file to phone using sftp.
  2. open file browser, go to folder where the .epub file is.
  3. tap on .epub file → properties page opens…
  4. Right click shows more properties of the file
  5. Pull down + open doesn’t start Books app but starts Browser chaos, see below.

EXPECTED RESULT:

.epub file opens with Books app and/or is automatically imported into Books app’s bookshelf.

ACTUAL RESULT:

tapping on .epub file in File Browser opens properties page of the file. Right tap opens further properties, pull down + open opens the Internet browser and starts some downloads that are difficult to stop by repeatedly closing the internet browser. (it pops up again several times) The “download” of the .epub file is visible in the list of downloads and the .epub file appears in the Downloads folder.

ADDITIONAL INFORMATION:

(Please ALWAYS attach relevant data such as logs, screenshots, etc…)

Suggestion: .epub filename extension should be assigned to books app, if missing to editor app, and never to browser app.

Disregarding the extension, what is the MIME type for the .ebub file?

Maybe it’s actually something like text/html because of some download failure or something like that it would explain why it’s opened by the browser.

The file type, shown on the file information page, is application/epub+zip

edit: once successfully imported into the books list of Books app, the book is readable and everything is fine.
But, the bug (in my opinion) is, that this filetype tries to open with internet browser and causes chaos if opened from File browser, although MIME type is application/epub+zip.