provide a public interface for acquiring changelogs

Provided is a specialized acquire item which given a version can figure
out the correct URI to try by itself and if not provides an error
message alongside with static methods to get just the URI it would try
to download if it should just be displayed or similar such.

The URI is constructed as follows:
Release files can provide an URI template in the "Changelogs" field,
otherwise we lookup a configuration item based on the "Label" or
"Origin" of the Release file to get a (hopefully known) default value
for now. This template should contain the string CHANGEPATH which is
replaced with the information about the version we want the changelog
for (e.g.  main/a/apt/apt_1.1). This middleway was choosen as this path
part was consistent over the three known implementations (+1 defunct),
while the rest of the URI varies widely between them.

The benefit of this construct is that it is now easy to get changelogs
for Debian packages on Ubuntu and vice versa – even at the moment where
the Changelogs field is present nowhere. Strictly better than what
apt-get had before as it would even fail to get changelogs from
security… Now it will notice that security identifies as Origin: Debian
and pick this setting (assuming again that no Changelogs field exists).
If on the other hand security would ship its changelogs in a different
location we could set it via the Label option overruling Origin.

Closes: 687147, 739854, 784027, 787190

1 files changed, 79 insertions, 25 deletions

diff --git a/test/integration/test-apt-get-changelog b/test/integration/test-apt-get-changelog
index 7e81c71b6..5fa8543b9 100755
--- a/test/integration/test-apt-get-changelog
+++ b/test/integration/test-apt-get-changelog
@@ -5,44 +5,98 @@ TESTDIR=$(readlink -f $(dirname $0))
 . $TESTDIR/framework
 
 setupenvironment
-configarchitecture "i386"
+configarchitecture 'native'
 
-buildsimplenativepackage 'apt' 'all' '1.0' 'stable'
+buildsimplenativepackage 'foo' 'all' '1.0' 'stable'
+buildsimplenativepackage 'libbar' 'all' '1.0' 'stable'
+
+getlabelfromsuite() { echo 'Testcases'; }
+getoriginfromsuite() { echo 'Debian'; }
 
 setupaptarchive --no-update
 changetowebserver
 testsuccess aptget update
 
-# simulate normal user with non-existent root-owned directories
-rm -rf rootdir/var/cache/apt/archives/
-mkdir rootdir/var/cache/apt/archives/
-addtrap 'prefix' "chmod -f -R +w $PWD/rootdir/var/cache/apt/archives || true;"
-chmod -R -w rootdir/var/cache/apt/archives
+testsuccessequal "'http://metadata.ftp-master.debian.org/changelogs/main/f/foo/foo_1.0_changelog' foo.changelog
+'http://metadata.ftp-master.debian.org/changelogs/main/libb/libbar/libbar_1.0_changelog' libbar.changelog" aptget changelog foo libbar --print-uris
+
+releasechanger() {
+	# modifying the Release files in lists… bad stuff. Good that this is only a test…
+	sed -i "s#^${1}: .*#${1}: ${2}#" $(find rootdir/var/lib/apt/lists -name '*Release')
+	rm -f rootdir/var/cache/apt/*.bin
+}
+releasechanger 'Origin' 'Ubuntu'
+testsuccessequal "'http://changelogs.ubuntu.com/changelogs/pool/main/f/foo/foo_1.0/changelog' foo.changelog
+'http://changelogs.ubuntu.com/changelogs/pool/main/libb/libbar/libbar_1.0/changelog' libbar.changelog" aptget changelog foo libbar --print-uris
+
+releasechanger 'Label' 'Debian'
+testsuccessequal "'http://changelogs.ubuntu.com/changelogs/pool/main/f/foo/foo_1.0/changelog' foo.changelog
+'http://changelogs.ubuntu.com/changelogs/pool/main/libb/libbar/libbar_1.0/changelog' libbar.changelog" aptget changelog foo libbar --print-uris
+
+testsuccessequal "'http://localhost:8080/main/f/foo/foo_1.0.changelog' foo.changelog
+'http://localhost:8080/main/libb/libbar/libbar_1.0.changelog' libbar.changelog" aptget changelog foo libbar --print-uris -o Acquire::Changelogs::URI::Label::Debian='http://localhost:8080/CHANGEPATH.changelog'
+
+sed -i '/^Origin: / a\
+Changelogs: http://example.org/CHANGEPATH-changelog' $(find rootdir/var/lib/apt/lists -name '*Release')
+rm -f rootdir/var/cache/apt/*.bin
 
-echo 'Apt::Changelogs::Server "http://localhost:8080/";' > rootdir/etc/apt/apt.conf.d/changelog.conf
+testsuccessequal "'http://example.org/main/f/foo/foo_1.0-changelog' foo.changelog
+'http://example.org/main/libb/libbar/libbar_1.0-changelog' libbar.changelog" aptget changelog foo libbar --print-uris -o Acquire::Changelogs::URI::Label::Debian='http://localhost:8080/CHANGEPATH.changelog'
 
-testsuccessequal "'http://localhost:8080/pool/apt_1.0/changelog'" aptget changelog apt --print-uris
+testsuccessequal "'http://localhost:8080/main/f/foo/foo_1.0.changelog' foo.changelog
+'http://localhost:8080/main/libb/libbar/libbar_1.0.changelog' libbar.changelog" aptget changelog foo libbar --print-uris -o Acquire::Changelogs::URI::Override::Label::Debian='http://localhost:8080/CHANGEPATH.changelog'
 
-testsuccessequal "'http://localhost:8080/pool/apt_1.0/changelog'
-'http://localhost:8080/pool/apt_1.0/changelog'" aptget changelog apt apt --print-uris
+releasechanger 'Changelogs' 'no'
+testequal 'E: Failed to fetch changelog:/foo.changelog  Changelog unavailable for foo=1.0
+' aptget changelog foo -qq -d
+
+sed -i '/^Changelogs: / d' $(find rootdir/var/lib/apt/lists -name '*Release')
+releasechanger 'Label' 'Testcases'
+
+echo 'Acquire::Changelogs::URI::Label::Testcases "http://localhost:8080/CHANGEPATH/change.txt";' > rootdir/etc/apt/apt.conf.d/changelog.conf
+testsuccessequal "'http://localhost:8080/main/f/foo/foo_1.0/change.txt' foo.changelog
+'http://localhost:8080/main/libb/libbar/libbar_1.0/change.txt' libbar.changelog" aptget changelog foo libbar --print-uris
+
+echo 'Acquire::Changelogs::URI::Label::Testcases "http://localhost:8080/pool/CHANGEPATH/changelog";' > rootdir/etc/apt/apt.conf.d/changelog.conf
+testsuccessequal "'http://localhost:8080/pool/main/f/foo/foo_1.0/changelog' foo.changelog" aptget changelog foo --print-uris
 
 cd downloaded
 
-testsuccess aptget changelog apt -qq
-testfileequal '../rootdir/tmp/testsuccess.output' "$(cat ../aptarchive/pool/apt_1.0/changelog)"
+testsuccess aptget changelog foo -qq
+testfileequal '../rootdir/tmp/testsuccess.output' "$(cat ../aptarchive/pool/main/f/foo/foo_1.0/changelog)"
+
+testsuccess aptget changelog foo libbar -qq
+testfileequal '../rootdir/tmp/testsuccess.output' "$(cat ../aptarchive/pool/main/f/foo/foo_1.0/changelog)
+$(cat ../aptarchive/pool/main/libb/libbar/libbar_1.0/changelog)"
+
+testsuccess aptget changelog foo -d
+testfilestats 'foo.changelog' '%U:%G:%a' '=' "${TEST_DEFAULT_USER}:${TEST_DEFAULT_GROUP}:644"
+testfileequal 'foo.changelog' "$(cat  ../aptarchive/pool/main/f/foo/foo_1.0/changelog)"
+rm -f foo.changelog
 
-testsuccess aptget changelog apt -d
-testfileequal 'apt.changelog' "$(cat  ../aptarchive/pool/apt_1.0/changelog)"
-testfilestats 'apt.changelog' '%U:%G:%a' '=' "${TEST_DEFAULT_USER}:${TEST_DEFAULT_GROUP}:644"
-rm -f apt.changelog ../aptarchive/pool/apt_1.0/changelog
+testsuccess aptget changelog libbar foo -d
+testfilestats 'libbar.changelog' '%U:%G:%a' '=' "${TEST_DEFAULT_USER}:${TEST_DEFAULT_GROUP}:644"
+testfilestats 'foo.changelog' '%U:%G:%a' '=' "${TEST_DEFAULT_USER}:${TEST_DEFAULT_GROUP}:644"
+testfileequal 'libbar.changelog' "$(cat  ../aptarchive/pool/main/libb/libbar/libbar_1.0/changelog)"
+testfileequal 'foo.changelog' "$(cat  ../aptarchive/pool/main/f/foo/foo_1.0/changelog)"
+rm -f libbar.changelog foo.changelog
 
-testequal "$(cat ../aptarchive/pool/apt_1.0.changelog)" aptget changelog apt \
-	-qq -o APT::Changelogs::Server='http://not-on-the-main-server:8080/'
+# as such bogus, but can happen with multiple binaries from the same source
+testsuccessequal "'http://localhost:8080/pool/main/f/foo/foo_1.0/changelog' foo.changelog
+'http://localhost:8080/pool/main/f/foo/foo_1.0/changelog' foo.changelog" aptget changelog foo foo --print-uris
+testsuccess aptget changelog foo foo -qq
+testfileequal '../rootdir/tmp/testsuccess.output' "$(cat ../aptarchive/pool/main/f/foo/foo_1.0/changelog)
+$(cat ../aptarchive/pool/main/f/foo/foo_1.0/changelog)"
+testsuccess aptget changelog foo foo -d
+testfilestats 'foo.changelog' '%U:%G:%a' '=' "${TEST_DEFAULT_USER}:${TEST_DEFAULT_GROUP}:644"
+testfileequal 'foo.changelog' "$(cat  ../aptarchive/pool/main/f/foo/foo_1.0/changelog)"
+rm -f foo.changelog
 
-testsuccess aptget changelog apt -d
-testfileequal 'apt.changelog' "$(cat ../aptarchive/pool/apt_1.0.changelog)"
-testfilestats 'apt.changelog' '%U:%G:%a' '=' "${TEST_DEFAULT_USER}:${TEST_DEFAULT_GROUP}:644"
-rm -f apt.changelog ../aptarchive/pool/apt_1.0.changelog
+# no CHANGEPATH in the URI
+testequal 'E: Failed to fetch changelog:/foo.changelog  Changelog unavailable for foo=1.0
+' aptget changelog foo -qq -d -o Acquire::Changelogs::URI::Label::Testcases='http://localhost:8080/change.txt'
+testfailure test -e foo.changelog
 
-testequal 'E: changelog download failed' aptget changelog apt -qq -d -o APT::Changelogs::Server='http://not-on-the-main-server:8080/'
-testfailure test -e apt.changelog
+testequal 'E: Failed to fetch http://localhost:8080/does/not/exist/main/f/foo/foo_1.0/change.txt  Changelog unavailable for foo=1.0 (404  Not Found)
+' aptget changelog foo -qq -d -o Acquire::Changelogs::URI::Label::Testcases='http://localhost:8080/does/not/exist/CHANGEPATH/change.txt'
+testfailure test -e foo.changelog