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

4 files changed, 103 insertions, 35 deletions

diff --git a/test/integration/framework b/test/integration/framework
index 7b03c09ef..1b99929e2 100644
--- a/test/integration/framework
+++ b/test/integration/framework
@@ -520,6 +520,12 @@ Package: $NAME" > debian/control
 
 buildsimplenativepackage() {
 	local NAME="$1"
+	local NM
+	if [ "$(echo "$NAME" | cut -c 1-3)" = 'lib' ]; then
+		NM="$(echo "$NAME" | cut -c 1-4)"
+	else
+		NM="$(echo "$NAME" | cut -c 1)"
+	fi
 	local ARCH="$2"
 	local VERSION="$3"
 	local RELEASE="${4:-unstable}"
@@ -600,15 +606,15 @@ Package: $NAME" >> ${BUILDDIR}/debian/control
 		(cd ${BUILDDIR}; dpkg-gencontrol -DArchitecture=$arch)
 		(cd ${BUILDDIR}/debian/tmp; md5sum $(find usr/ -type f) > DEBIAN/md5sums)
 		local LOG="${BUILDDIR}/../${NAME}_${VERSION}_${arch}.dpkg-deb.log"
-		# ensure the right permissions as dpkg-deb ensists
+		# ensure the right permissions as dpkg-deb insists
 		chmod 755 ${BUILDDIR}/debian/tmp/DEBIAN
 		testsuccess --nomsg dpkg-deb -Z${COMPRESS_TYPE} --build ${BUILDDIR}/debian/tmp ${BUILDDIR}/..
 		echo "pool/${NAME}_${VERSION}_${arch}.deb" >> ${BUILDDIR}/../${RELEASE}.${DISTSECTION}.pkglist
 	done
 
-	mkdir -p ${BUILDDIR}/../${NAME}_${VERSION}
-	cp ${BUILDDIR}/debian/changelog ${BUILDDIR}/../${NAME}_${VERSION}/
-	cp ${BUILDDIR}/debian/changelog ${BUILDDIR}/../${NAME}_${VERSION}.changelog
+	local CHANGEPATH="${BUILDDIR}/../${DISTSECTION}/${NM}/${NAME}/${NAME}_${VERSION}"
+	mkdir -p $CHANGEPATH
+	cp ${BUILDDIR}/debian/changelog $CHANGEPATH
 	rm -rf "${BUILDDIR}"
 	msgdone "info"
 }
@@ -876,6 +882,7 @@ getcodenamefromsuite() {
 }
 getreleaseversionfromsuite() { true; }
 getlabelfromsuite() { true; }
+getoriginfromsuite() { true; }
 
 generatereleasefiles() {
 	# $1 is the Date header and $2 is the ValidUntil header to be set
@@ -887,16 +894,21 @@ generatereleasefiles() {
 			local CODENAME="$(getcodenamefromsuite $SUITE)"
 			local VERSION="$(getreleaseversionfromsuite $SUITE)"
 			local LABEL="$(getlabelfromsuite $SUITE)"
+			local ORIGIN="$(getoriginfromsuite $SUITE)"
 			if [ -n "$VERSION" ]; then
 				VERSION="-o APT::FTPArchive::Release::Version=${VERSION}"
 			fi
 			if [ -n "$LABEL" ]; then
 				LABEL="-o APT::FTPArchive::Release::Label=${LABEL}"
 			fi
+			if [ -n "$ORIGIN" ]; then
+				ORIGIN="-o APT::FTPArchive::Release::Origin=${ORIGIN}"
+			fi
 			aptftparchive -qq release $dir \
 				-o APT::FTPArchive::Release::Suite="${SUITE}" \
 				-o APT::FTPArchive::Release::Codename="${CODENAME}" \
 				${LABEL} \
+				${ORIGIN} \
 				${VERSION} \
 					| sed -e '/0 Release$/ d' > $dir/Release # remove the self reference
 			if [ "$SUITE" = "experimental" -o "$SUITE" = "experimental2" ]; then
@@ -1450,9 +1462,9 @@ testfilestats() {
 		msgpass
 	else
 		echo >&2
-		ls -ld >&2 "$1"
+		ls -ld >&2 "$1" || true
 		echo -n >&2 "stat(1) reports for $2: "
-		stat --format "$2" "$1"
+		stat --format "$2" "$1" || true
 		msgfail
 	fi
 }
diff --git a/test/integration/test-apt-get-changelog b/test/integration/test-apt-get-changelog
index 7e81c71b6..5fa8543b9 100755
--- a/test/integration/test-apt-get-changelog
+++ b/test/integration/test-apt-get-changelog
@@ -5,44 +5,98 @@ TESTDIR=$(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
diff --git a/test/integration/test-bug-722207-print-uris-even-if-very-quiet b/test/integration/test-bug-722207-print-uris-even-if-very-quiet
index 2cad929cc..e51d72ccd 100755
--- a/test/integration/test-bug-722207-print-uris-even-if-very-quiet
+++ b/test/integration/test-bug-722207-print-uris-even-if-very-quiet
@@ -12,6 +12,7 @@ insertpackage 'unstable' 'apt' 'all' '2'
 insertsource 'unstable' 'apt' 'all' '2'
 insertsource 'unstable' 'apt2' 'all' '1'
 
+getoriginfromsuite() { echo 'Debian'; }
 setupaptarchive
 
 APTARCHIVE=$(readlink -f ./aptarchive)
@@ -22,7 +23,7 @@ testsuccessequal "'file://${APTARCHIVE}/pool/main/apt/apt_2_all.deb' apt_2_all.d
 testsuccessequal "'file://${APTARCHIVE}/pool/main/apt/apt_2_all.deb' apt_2_all.deb 0 " aptget download apt -qq --print-uris
 testsuccessequal "'file://${APTARCHIVE}/apt_2.dsc' apt_2.dsc 0 MD5Sum:d41d8cd98f00b204e9800998ecf8427e
 'file://${APTARCHIVE}/apt_2.tar.gz' apt_2.tar.gz 0 MD5Sum:d41d8cd98f00b204e9800998ecf8427e" aptget source apt -qq --print-uris
-testsuccessequal "'http://packages.debian.org/changelogs/pool/main/apt/apt_2/changelog'" aptget changelog apt -qq --print-uris
+testsuccessequal "'http://metadata.ftp-master.debian.org/changelogs/main/a/apt/apt_2_changelog' apt.changelog" aptget changelog apt -qq --print-uris
 
 testsuccessequal "'file://${APTARCHIVE}/apt_2.dsc' apt_2.dsc 0 MD5Sum:d41d8cd98f00b204e9800998ecf8427e
 'file://${APTARCHIVE}/apt_2.tar.gz' apt_2.tar.gz 0 MD5Sum:d41d8cd98f00b204e9800998ecf8427e
diff --git a/test/integration/test-bug-738785-switch-protocol b/test/integration/test-bug-738785-switch-protocol
index f6336ffe3..539080200 100755
--- a/test/integration/test-bug-738785-switch-protocol
+++ b/test/integration/test-bug-738785-switch-protocol
@@ -10,6 +10,7 @@ configarchitecture "i386"
 buildsimplenativepackage 'apt' 'all' '1.0' 'stable'
 
 # setup http redirecting to https
+getlabelfromsuite() { echo 'Testcases'; }
 setupaptarchive --no-update
 changetowebserver -o 'aptwebserver::redirect::replace::/redirectme/=https://localhost:4433/' \
 	-o 'aptwebserver::redirect::replace::/downgrademe/=http://localhost:8080/' \
@@ -20,10 +21,10 @@ sed -i -e 's#:4433/#:8080/redirectme#' -e 's# https:# http:#' rootdir/etc/apt/so
 testsuccess aptget update -o Debug::Acquire::http=1 -o Debug::Acquire::https=1 -o Debug::pkgAcquire::Worker=1
 
 msgtest 'Test that the webserver does not answer' 'http requests'
-downloadfile 'http://localhost:8080/pool/apt_1.0/changelog' changelog >/dev/null 2>&1 && msgfail || msgpass
+downloadfile 'http://localhost:8080/pool/main/a/apt/apt_1.0/changelog' changelog >/dev/null 2>&1 && msgfail || msgpass
 
-echo 'Apt::Changelogs::Server "http://localhost:8080/redirectme";' > rootdir/etc/apt/apt.conf.d/changelog.conf
-testsuccessequal "'http://localhost:8080/redirectme/pool/apt_1.0/changelog'" aptget changelog apt --print-uris
+echo 'Acquire::Changelogs::URI::Label::Testcases "http://localhost:8080/redirectme/pool/CHANGEPATH/changelog";' > rootdir/etc/apt/apt.conf.d/changelog.conf
+testsuccessequal "'http://localhost:8080/redirectme/pool/main/a/apt/apt_1.0/changelog' apt.changelog" aptget changelog apt --print-uris
 
 cd downloaded
 testsuccess aptget changelog apt -d