update: keep CVC of an app out of the archive

We want to keep the stable version (CV) of an app in /repo with highest
priority and only move it to /archive when ArchivePolicy is set to 0.

For this to work we need two changes here:

1) when sorting apks by version code we insert the apk corresponding to
the CVC of the app afterwards with highest priority. So when walking the
list of apks afterwards the CVC apk is always kept first.

2) Instead of the two pass algorithm of moving things back and forth to
the archive we instead figure out where each apk of an app goes in first
before actually moving them into the right place.

Fixes: fdroid/fdroidserver#385

fdroidserver/update.py

@@ -1823,12 +1823,20 @@ def archive_old_apks(apps, apks, archapks, repodir, archivedir, defaultkeepversi
 
     def filter_apk_list_sorted(apk_list):
         res = []
+        currentVersionApk = None
         for apk in apk_list:
             if apk['packageName'] == appid:
+                if apk['versionCode'] == common.version_code_string_to_int(app.CurrentVersionCode):
+                    currentVersionApk = apk
+                    continue
                 res.append(apk)
 
         # Sort the apk list by version code. First is highest/newest.
-        return sorted(res, key=lambda apk: apk['versionCode'], reverse=True)
+        sorted_list = sorted(res, key=lambda apk: apk['versionCode'], reverse=True)
+        if currentVersionApk:
+            # Insert apk which corresponds to currentVersion at the front
+            sorted_list.insert(0, currentVersionApk)
+        return sorted_list
 
     for appid, app in apps.items():
 
@@ -1840,26 +1848,28 @@ def archive_old_apks(apps, apks, archapks, repodir, archivedir, defaultkeepversi
         logging.debug(_("Checking archiving for {appid} - apks:{integer}, keepversions:{keep}, archapks:{arch}")
                       .format(appid=appid, integer=len(apks), keep=keepversions, arch=len(archapks)))
 
-        current_app_apks = filter_apk_list_sorted(apks)
+        all_app_apks = filter_apk_list_sorted(apks + archapks)
-        if len(current_app_apks) > keepversions:
-            # Move back the ones we don't want.
-            for apk in current_app_apks[keepversions:]:
-                move_apk_between_sections(repodir, archivedir, apk)
-                archapks.append(apk)
-                apks.remove(apk)
 
-        current_app_archapks = filter_apk_list_sorted(archapks)
+        # determine which apks to keep in repo
-        if len(current_app_apks) < keepversions and len(current_app_archapks) > 0:
+        keep = []
-            kept = 0
+        for apk in all_app_apks:
-            # Move forward the ones we want again, except DisableAlgorithm
+            if len(keep) == keepversions:
-            for apk in current_app_archapks:
+                break
-                if 'DisabledAlgorithm' not in apk['antiFeatures']:
+            if 'antiFeatures' not in apk:
-                    move_apk_between_sections(archivedir, repodir, apk)
+                keep.append(apk)
+            elif 'DisabledAlgorithm' not in apk['antiFeatures']:
+                keep.append(apk)
+
+        # actually move apks to the target section
+        for apk in all_app_apks:
+            if apk in apks and apk not in keep:
+                apks.remove(apk)
+                archapks.append(apk)
+                move_apk_between_sections(repodir, archivedir, apk)
+            elif apk in archapks and apk in keep:
                 archapks.remove(apk)
                 apks.append(apk)
-                    kept += 1
+                move_apk_between_sections(archivedir, repodir, apk)
-                if kept == keepversions:
-                    break
 
 
 def move_apk_between_sections(from_dir, to_dir, apk):