invalid cache if architecture set doesn't match

The cache heavily depends on the architecture(s) it is build for,
especially if you move from single- to multiarch. Adding a new
architecture to dpkg therefore has to be detected and must invalidate
the cache so that we don't operate on incorrect data.

The incorrect data will prevent us from doing otherwise sensible
actions (it doesn't allow bad things to happen) and the recovery is
simple and automatic in most cases, so this hides pretty well and is
also not as serious as it might sound at first.

Closes: 745036

1 files changed, 29 insertions, 0 deletions

diff --git a/test/integration/test-bug-745036-new-foreign-invalidates-cache b/test/integration/test-bug-745036-new-foreign-invalidates-cache
new file mode 100755
index 000000000..490cbecdd
--- /dev/null
+++ b/test/integration/test-bug-745036-new-foreign-invalidates-cache
@@ -0,0 +1,29 @@
+#!/bin/sh
+set -e
+
+TESTDIR=$(readlink -f $(dirname $0))
+. $TESTDIR/framework
+setupenvironment
+configarchitecture 'amd64'
+
+insertpackage 'unstable' 'cool-foo' 'amd64' '1.0' 'Depends: foo'
+insertpackage 'unstable' 'foo' 'amd64' '1.0' 'Multi-Arch: foreign'
+insertinstalledpackage 'cool-foo' 'amd64' '1.0' 'Depends: foo'
+insertinstalledpackage 'foo' 'amd64' '1.0' 'Multi-Arch: foreign'
+
+setupaptarchive
+
+testsuccess aptget check -s
+
+configarchitecture 'amd64' 'i386'
+testequal 'E: The package cache was built for different architectures: amd64 vs amd64,i386' aptget check -s -o pkgCacheFile::Generate=false
+
+testsuccess aptget check -s
+
+insertinstalledpackage 'awesome-foo' 'i386' '1.0' 'Depends: foo'
+
+testsuccess aptget check -s
+
+testsuccess aptget update --no-download
+
+testsuccess aptget check -s