Drop the composite vercode + repo primary key from apk table

We expect repos to serve multiple apks with the same version code but
different signing certificates in the future.

app/src/main/java/org/fdroid/fdroid/data/DBHelper.java

@@ -108,8 +108,7 @@ class DBHelper extends SQLiteOpenHelper {
             + ApkTable.Cols.ADDED_DATE + " string, "
             + ApkTable.Cols.IS_COMPATIBLE + " int not null, "
             + ApkTable.Cols.INCOMPATIBLE_REASONS + " text, "
-            + ApkTable.Cols.ANTI_FEATURES + " string, "
-            + "PRIMARY KEY (" + ApkTable.Cols.APP_ID + ", " + ApkTable.Cols.VERSION_CODE + ", " + ApkTable.Cols.REPO_ID + ")"
+            + ApkTable.Cols.ANTI_FEATURES + " string"
             + ");";
 
     static final String CREATE_TABLE_APP_METADATA = "CREATE TABLE " + AppMetadataTable.NAME
@@ -193,7 +192,7 @@ class DBHelper extends SQLiteOpenHelper {
             + InstalledAppTable.Cols.HASH + " TEXT NOT NULL"
             + " );";
 
-    protected static final int DB_VERSION = 69;
+    protected static final int DB_VERSION = 70;
 
     private final Context context;
 
@@ -277,6 +276,18 @@ class DBHelper extends SQLiteOpenHelper {
         addIndexV1AppFields(db, oldVersion);
         recalculatePreferredMetadata(db, oldVersion);
         addWhatsNewAndVideo(db, oldVersion);
+        dropApkPrimaryKey(db, oldVersion);
+    }
+
+    private void dropApkPrimaryKey(SQLiteDatabase db, int oldVersion) {
+        if (oldVersion >= 70) {
+            return;
+        }
+
+        // versionCode + repo is no longer a valid primary key given a repo can have multiple apks
+        // with the same versionCode, signed by different certificates.
+        Log.i(TAG, "Dropping composite primary key on apk table in favour of sqlite's rowid");
+        resetTransient(db);
     }
 
     private void addWhatsNewAndVideo(SQLiteDatabase db, int oldVersion) {

app/src/test/java/org/fdroid/fdroid/data/SuggestedVersionTest.java

@@ -73,11 +73,6 @@ public class SuggestedVersionTest extends FDroidProviderTest {
         assertEquals(3, found3.suggestedVersionCode);
     }
 
-    /**
-     * TODO: Failing for two reasons:
-     *  * We don't support suggested versioncode with multi-sig.
-     *  * More importantly, we don't even support multi-sig due to the [appId, vercode, repo] primary key.
-     */
     @Test
     public void singleRepoMultiSig() {
         App singleApp = insertApp(context, "single.app", "Single App", 4, "https://simple.repo");