Update MuPDF to 1.12

[KrasnayaPloshchad]

With MuPDF 1.12 you could making build easier. Here is the release notes copied from official website:

MuPDF 1.12.0 (2017-12-13)

You can now download the 1.12.0 release.
MuPDF 1.12-rc1 (2017-11-23)

The release candidate for version 1.12 is now available!

This release has a new Android SDK which is easier to use.

These are the git repositories for the SDK projects:

    mupdf-android-fitz.git has the JNI bindings in a library.
    mupdf-android-viewer.git has the viewer as an activity in a library.
    mupdf-android-viewer-mini.git has the minimalist viewer as an activity in a library. 

There are binary packages for these libraries in our Maven repository:

    com.artifex.mupdf:fitz:1.12.+
    com.artifex.mupdf:viewer:1.12.+
    com.artifex.mupdf:mini:1.12.+ 

Color Management:

    LCMS2 library for color management.
    CMYK rendering with overprint simulation.
    Spot color rendering.
    Transparency rendering fixes. 

Structured text output improvements:

    Reworked structured text API.
    Faster text searching.
    Highlight and copy text by selecting lines instead of by area.
    New semantic XHTML output format.
    New layout preserving HTML output format. 

Features and improvements:

    Improved non-AA rendering with new scan converter.
    Improved LARGEFILE support.
    Improved TIFF support.
    Improved documentation.
    PCLm output.
    PSD output.
    New "mutool trace" tool.
    New "mutool sign" tool (work in progress).
    Text redaction (work in progress). 

Lots of bug fixes. 

[sss]

Seems difficult to maintain our C part 😢 I'm working to switch to Java API. See #267.

[ildar]

Phase note that it (probably) fixes many security issues

[matsievskiysv]

Updated to the latest MuPDF version on dev branch

[SkewedZeppelin]

I am going though apps that use old native libraries on F-Droid: https://gitlab.com/fdroid/fdroiddata/-/merge_requests/11496/

The currently used MuPDF 1.11 from 2017-04-11 seems to have 27 known security issues, accounting for the 4 patched. https://github.com/SufficientlySecure/document-viewer/commits/v2.8.2/document-viewer/jni/mupdf https://github.com/SufficientlySecure/document-viewer/commit/0bfb13b1b65cc27145b4526a3c2564ecdb468674

MuPDF 1.20.0 is now out: https://mupdf.com/releases/history.html

What is the status of this?

[matsievskiysv]

@SkewedZeppelin AFAIK this project does not have a maintainer.

[woj-tek]

Maybe it would be sensible to fork it? There was some work done by @matsievskiysv and @sss . Maybe just coordinate it a bit?