fix: prevent db cleanup from deleting AppStream pool files

system/t08_db/CleanupDB13Test_gold

@@ -0,0 +1,7 @@
+Loading mirrors, local repos, snapshots and published repos...
+Loading list of all packages...
+Deleting unreferenced packages (0)...
+Building list of files referenced by packages...
+Building list of files in package pool...
+Deleting unreferenced files (0)...
+Compacting database...

system/t08_db/CleanupDB13Test_publish

@@ -0,0 +1,14 @@
+Loading packages...
+Generating metadata files and linking package files...
+[!] Failed to generate package contents:  unable to read .deb archive from amanda-client_3.3.1-3~bpo60+1_amd64.deb: ar: missing global header
+Finalizing metadata files...
+Signing file 'Release' with gpg, please enter your passphrase when prompted:
+Clearsigning file 'Release' with gpg, please enter your passphrase when prompted:
+
+Snapshot snap-appstream has been successfully published.
+Please setup your webserver to serve directory '${HOME}/.aptly/public' with autoindexing.
+Now you can add following line to apt sources:
+  deb http://your-server/ hardy main
+Don't forget to add your GPG key to apt with apt-key.
+
+You can also use `aptly serve` to publish your repositories over HTTP quickly.

system/t08_db/cleanup.py

@@ -150,3 +150,27 @@ class CleanupDB12Test(BaseTest):
         "aptly mirror drop gnuplot-maverick",
     ]
     runCmd = "aptly db cleanup -verbose -dry-run"
+
+
+class CleanupDB13Test(BaseTest):
+    """
+    cleanup db: appstream files survive cleanup
+    """
+    fixtureWebServer = "../t04_mirror/test_release2"
+    fixtureGpg = True
+    configOverride = {"downloadRetries": 0}
+    fixtureCmds = [
+        "aptly mirror create --ignore-signatures -with-appstream -architectures=amd64 appstream-test ${url} hardy main",
+        "aptly mirror update -ignore-checksums --ignore-signatures appstream-test",
+        "aptly snapshot create snap-appstream from mirror appstream-test",
+    ]
+    runCmd = "aptly db cleanup"
+
+    def check(self):
+        self.check_output()
+        # verify appstream files survive cleanup by publishing the snapshot
+        self.check_cmd_output(
+            "aptly publish snapshot -keyring=${files}/aptly.pub -secret-keyring=${files}/aptly.sec snap-appstream",
+            "publish", match_prepare=self.expand_environ)
+        self.check_exists('public/dists/hardy/main/dep11/Components-amd64.yml.gz')
+        self.check_exists('public/dists/hardy/main/dep11/icons-48x48.tar.gz')