Adobe non free code in type 1 fonts

The problem

Font hinting used to contain some proprietary code by Adobe, which was relicensed to Apache-2.0. That code is described here:

adobe code fragment (via archive.org)
Black book page 97 available here (via archive.org)

There is also proprietary code by Adobe implementing routines for multiple master fonts. This was not relicensed.

How can I check

Lintian help see report here

Install the t1utils package and run the following command on the pfb file:

t1disasm file.pfb

Check if you see the non-free code.

If you only the the lines

{systemdict /internaldict known not
{pop 3}
{1183615869 systemdict /internaldict get exec
dup /startlock known
{/startlock get exec}
{dup /strtlck known
{/strtlck get exec}
{pop 3}
ifelse}
ifelse}
ifelse
} executeonly
] noaccess def

You may be on the good side, since this fragment and related fragments were created by Adobe but are now under Apache-2.0 license, brought to us via AFDKO (Adobe Font Development Kit for Opentype), see https://sources.debian.org/src/afdko/4.0.1%2Bdfsg1-2/c/shared/source/t1write in afdko packge.

Lintian may be a little too aggressively here and complain about the above lines.

How to solve

Rewriting is difficult:

the adobe code is part of the language
some printers search and replace the adobe code by their own routine. Rewritting this code could crash your printer.
the adobe code is buggy (leaks memory) and postscript interpreters patch it at run time. Modifying it could change the postscript interpreter behavior.

I found this bug

Please report this bug by adding to the bug header the following usertag:

user: debian-qa@lists.debian.org
usertags: adobe-font-license
severity: serious

See usertags documentation for more information about usertags.

List of this kind of bug

Please see the list

qa.debian.orgtype1nondfsg