Bug#1033135: qt6-webengine: Remove old Unicode DFSG-non-free license

[Soren Stoutner]

Source: qt6-webengine
Version: 6.4.2-final+dfsg-1
Severity: wishlist
Tags: upstream

Unicode produced a number of files years ago that contained a problematic license with the following restriction:

"Unicode, Inc. hereby grants the right to freely use the information supplied in this file in the creation of products supporting the Unicode Standard"

This is not free because it prevents the use of the file in ways that do not support the Unicode standard.

In 2004 Unicode relicensed their files under a different license that does not contain this restriction.

These is their current copyright and terms of use statement:

http://www.unicode.org/copyright.html

Which links to their current license:

https://www.unicode.org/license.txt

For many years, Chromium integrated an older copy of `Convert-UTF` with the problematic license. When the problem was brought to their attention they updated the file's license.

https://bugs.chromium.org/p/google-breakpad/issues/detail?id=270

https://chromium.googlesource.com/breakpad/breakpad/+/14bbefbd9600e08d6a34d7250faa8bc9dba2113e%5E%21/

qt6-webengine currently includes three other files that still contain this problematic license in their headers.

src/3rdparty/chromium/third_party/icu/source/data/mappings/iso-8859_10-1998.ucm
src/3rdparty/chromium/third_party/icu/source/data/mappings/iso-8859_11-2001.ucm
src/3rdparty/chromium/third_party/icu/source/data/mappings/iso-8859_14-1998.ucm

Identical files (except for the licenses) are found in the Unicode GitHub repository:

https://github.com/unicode-org/icu/tree/main/icu4c/source/data/mappings

These were updated to the non-problematic license in 2015:

https://unicode-org.atlassian.net/browse/ICU-22007

A copy of the bad license also appears in:

src/3rdparty/chromium/third_party/breakpad/breakpad/LICENSE

It needs to be removed, and, if breakpad uses the ICU files, replaced with the license at:

https://www.unicode.org/license.txt

This has been reported upstream at:

https://bugreports.qt.io/browse/QTBUG-112008

There is also a Lintian bug regarding the detection of this problematic license:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=854209