Bug#538691: opencascade: FTBFS with new source format 3.0 (quilt): fail to unapply quilt patches applied by dpkg-source

[hertzog at debian.org]

Package: opencascade
Version: 6.3.0.dfsg.1-3
Severity: wishlist
Usertags: 3.0-quilt-by-default

To prepare a possible switch to the new source package format "3.0
(quilt)" [1], I converted all source packages and rebuilt the packages
afterwards to see what breaks, and opencascade does break. To reproduce the
problem you can do this:
$ apt-get source opencascade
$ mkdir -p opencascade-6.3.0.dfsg.1/debian/source
$ echo "3.0 (quilt)" >opencascade-6.3.0.dfsg.1/debian/source/format
$ dpkg-source -b opencascade-6.3.0.dfsg.1
$ dpkg-source -x opencascade_6.3.0.dfsg.1-3.dsc
$ cd opencascade-6.3.0.dfsg.1 && debuild -us -uc

In this process, if the .diff.gz contains changes to upstream files,
dpkg-source will have created a corresponding patch in
debian/patches/debian-changes-6.3.0.dfsg.1-3 and will have registered that
patch in a quilt series (debian/patches/series, it is created if needed).
All the patches listed in the "series" file are applied directly during
the extraction (dpkg-source -x). quilt itself is used if available (and
will thus lead to the creation of the .pc directory), otherwise
dpkg-source applies the patches by itself. For more information about the
new source package format see the manual page dpkg-source(1).

In the case of opencascade, the clean target does not unapply patches
applied by dpkg-source because dpkg-source does not create the expected
stamp file, yet it will remove the .pc directory in all cases... thus
the quilt metadinformation get out of sync and will later fail trying to
reapply patches that are already applied.

Cheers,

[1] http://wiki.debian.org/Projects/DebSrc3.0