Bug#485021: powermanga: FTBFS when converted to new source format 3.0 (quilt): patch invalid, missing context

[Raphael Hertzog]

Package: powermanga
Version: 0.90-dfsg-1
Severity: minor
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 tried to rebuild them.
Unfortunately, powermanga failed, you can try yourself with those
commands (and dpkg-dev >= 1.14.19 [2]) :

$ apt-get source powermanga
$ sed -i -e '/^Source:/ aFormat: 3.0 (quilt)' powermanga-0.90-dfsg/debian/control
$ dpkg-source -b powermanga-0.90-dfsg
$ dpkg-source -x powermanga_0.90-dfsg-1.dsc
$ cd powermanga-0.90-dfsg && 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-0.90-dfsg-1 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 powermanga, it contains patches that are invalid. Some
context lines are missing according to the header line (the one with
@@ inside). You should "quilt refresh" the patches and bring them back
into shape.

As a side note, you must also pay attention to the following points in
your quilt usage to guarantee compatibility with the new source package
format:
- all your patches must be applicable with the "-p1" option of patch
  (and you shouldn't use options in the series file to override this)
- the patches must be in debian/patches/ together with the "series" file
  (you can use QUILT_PATCHES=debian/patches if needed)
- you should not override QUILT_PC to change the location of quilt's
  internal directory (".pc" by default)
- the patches should not reference absolute filenames (in +++/--- lines)
- your clean target must work even if the patches are already applied
- your build target must work with patches applied even if the clean
  target is supposed to unapply them (because dpkg-source -b might
  have applied them back)

Cheers,

[1] http://lists.debian.org/debian-devel-announce/2008/04/msg00004.html
[2] the upcoming dpkg-dev 1.14.20 is more tolerant with patches, you can
grab it here if you want to try with that version:
http://people.debian.org/~hertzog/packages/dpkg-dev_1.14.20_all.deb
-- 
Raphael Hertzog