Add "preferredSigner" field to App.

At present, this is chosen from the first package in the index-v1
metadata.

app/src/main/java/org/fdroid/fdroid/IndexV1Updater.java

@@ -217,9 +217,14 @@ public class IndexV1Updater extends RepoUpdater {
                 if (packages != null) {
                     apks = packages.get(app.packageName);
                 }
+
                 if (apks == null) {
                     Log.i(TAG, "processIndexV1 empty packages");
-                    apks = new ArrayList<Apk>(0);
+                    apks = new ArrayList<>(0);
+                }
+
+                if (apks.size() > 0) {
+                    app.preferredSigner = apks.get(0).sig;
                 }
 
                 if (appCount % 50 == 0) {

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

@@ -8,6 +8,7 @@ import android.database.Cursor;
 import android.net.Uri;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.text.TextUtils;
 import android.util.Log;
 
 import org.fdroid.fdroid.data.Schema.ApkTable;
@@ -75,8 +76,22 @@ public class ApkProvider extends FDroidProvider {
             return resolver.delete(uri, null, null);
         }
 
+        /**
+         * Find an app which is closest to the version code suggested by the server, with some caveates:
+         * <ul>
+         *     <li>If installed, limit to apks signed by the same signer as the installed apk.</li>
+         *     <li>Otherwise, limit to apks signed by the "preferred" signer (see {@link App#preferredSigner}).</li>
+         * </ul>
+         */
         public static Apk findSuggestedApk(Context context, App app) {
-            return findApkFromAnyRepo(context, app.packageName, app.suggestedVersionCode, app.installedSig);
+            String preferredSignature = null;
+            if (!TextUtils.isEmpty(app.installedSig)) {
+                preferredSignature = app.installedSig;
+            } else if (!TextUtils.isEmpty(app.preferredSigner)) {
+                preferredSignature = app.preferredSigner;
+            }
+
+            return findApkFromAnyRepo(context, app.packageName, app.suggestedVersionCode, preferredSignature);
         }
 
         public static Apk findApkFromAnyRepo(Context context, String packageName, int versionCode) {

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

@@ -98,6 +98,8 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
     private long id;
     @JsonIgnore
     private AppPrefs prefs;
+    @JsonIgnore
+    public String preferredSigner;
 
     @JacksonInject("repoId")
     public long repoId;
@@ -286,6 +288,9 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
                 case Cols.SuggestedApk.VERSION_NAME:
                     suggestedVersionName = cursor.getString(i);
                     break;
+                case Cols.PREFERRED_SIGNER:
+                    preferredSigner = cursor.getString(i);
+                    break;
                 case Cols.SUGGESTED_VERSION_CODE:
                     suggestedVersionCode = cursor.getInt(i);
                     break;
@@ -828,6 +833,7 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
         values.put(Cols.FLATTR_ID, flattrID);
         values.put(Cols.ADDED, Utils.formatDate(added, ""));
         values.put(Cols.LAST_UPDATED, Utils.formatDate(lastUpdated, ""));
+        values.put(Cols.PREFERRED_SIGNER, preferredSigner);
         values.put(Cols.SUGGESTED_VERSION_CODE, suggestedVersionCode);
         values.put(Cols.UPSTREAM_VERSION_NAME, upstreamVersionName);
         values.put(Cols.UPSTREAM_VERSION_CODE, upstreamVersionCode);
@@ -1003,6 +1009,7 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
         dest.writeString(this.bitcoin);
         dest.writeString(this.litecoin);
         dest.writeString(this.flattrID);
+        dest.writeString(this.preferredSigner);
         dest.writeString(this.upstreamVersionName);
         dest.writeInt(this.upstreamVersionCode);
         dest.writeString(this.suggestedVersionName);
@@ -1050,6 +1057,7 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
         this.bitcoin = in.readString();
         this.litecoin = in.readString();
         this.flattrID = in.readString();
+        this.preferredSigner = in.readString();
         this.upstreamVersionName = in.readString();
         this.upstreamVersionCode = in.readInt();
         this.suggestedVersionName = in.readString();

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

@@ -128,6 +128,7 @@ class DBHelper extends SQLiteOpenHelper {
             + AppMetadataTable.Cols.SOURCE_CODE + " text, "
             + AppMetadataTable.Cols.VIDEO + " string, "
             + AppMetadataTable.Cols.CHANGELOG + " text, "
+            + AppMetadataTable.Cols.PREFERRED_SIGNER + " text,"
             + AppMetadataTable.Cols.SUGGESTED_VERSION_CODE + " text,"
             + AppMetadataTable.Cols.UPSTREAM_VERSION_NAME + " text,"
             + AppMetadataTable.Cols.UPSTREAM_VERSION_CODE + " integer,"
@@ -192,7 +193,7 @@ class DBHelper extends SQLiteOpenHelper {
             + InstalledAppTable.Cols.HASH + " TEXT NOT NULL"
             + " );";
 
-    protected static final int DB_VERSION = 71;
+    protected static final int DB_VERSION = 72;
 
     private final Context context;
 
@@ -278,6 +279,18 @@ class DBHelper extends SQLiteOpenHelper {
         addWhatsNewAndVideo(db, oldVersion);
         dropApkPrimaryKey(db, oldVersion);
         addIntegerPrimaryKeyToInstalledApps(db, oldVersion);
+        addPreferredSignerToApp(db, oldVersion);
+    }
+
+    private void addPreferredSignerToApp(SQLiteDatabase db, int oldVersion) {
+        if (oldVersion >= 72) {
+            return;
+        }
+
+        if (!columnExists(db, AppMetadataTable.NAME, AppMetadataTable.Cols.PREFERRED_SIGNER)) {
+            Log.i(TAG, "Adding preferred signer to app table.");
+            db.execSQL("alter table " + AppMetadataTable.NAME + " add column " + AppMetadataTable.Cols.PREFERRED_SIGNER + " text;");
+        }
     }
 
     private void addIntegerPrimaryKeyToInstalledApps(SQLiteDatabase db, int oldVersion) {

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

@@ -136,6 +136,7 @@ public interface Schema {
             String BITCOIN = "bitcoinAddr";
             String LITECOIN = "litecoinAddr";
             String FLATTR_ID = "flattrID";
+            String PREFERRED_SIGNER = "preferredSigner";
             String SUGGESTED_VERSION_CODE = "suggestedVercode";
             String UPSTREAM_VERSION_NAME = "upstreamVersion";
             String UPSTREAM_VERSION_CODE = "upstreamVercode";
@@ -192,7 +193,7 @@ public interface Schema {
                     ANTI_FEATURES, REQUIREMENTS, ICON_URL, ICON_URL_LARGE,
                     FEATURE_GRAPHIC, PROMO_GRAPHIC, TV_BANNER, PHONE_SCREENSHOTS,
                     SEVEN_INCH_SCREENSHOTS, TEN_INCH_SCREENSHOTS, TV_SCREENSHOTS, WEAR_SCREENSHOTS,
-                    SUGGESTED_VERSION_CODE,
+                    PREFERRED_SIGNER, SUGGESTED_VERSION_CODE,
             };
 
             /**
@@ -208,7 +209,7 @@ public interface Schema {
                     ANTI_FEATURES, REQUIREMENTS, ICON_URL, ICON_URL_LARGE,
                     FEATURE_GRAPHIC, PROMO_GRAPHIC, TV_BANNER, PHONE_SCREENSHOTS,
                     SEVEN_INCH_SCREENSHOTS, TEN_INCH_SCREENSHOTS, TV_SCREENSHOTS, WEAR_SCREENSHOTS,
-                    SUGGESTED_VERSION_CODE, SuggestedApk.VERSION_NAME,
+                    PREFERRED_SIGNER, SUGGESTED_VERSION_CODE, SuggestedApk.VERSION_NAME,
                     InstalledApp.VERSION_CODE, InstalledApp.VERSION_NAME,
                     InstalledApp.SIGNATURE, Package.PACKAGE_NAME,
             };

app/src/test/java/org/fdroid/fdroid/TestUtils.java

@@ -92,10 +92,11 @@ public class TestUtils {
     }
 
     public static App insertApp(Context context, String packageName, String appName, int upstreamVersionCode,
-                          Repo repo) {
+                          Repo repo, String preferredSigner) {
         ContentValues values = new ContentValues();
         values.put(Schema.AppMetadataTable.Cols.REPO_ID, repo.getId());
         values.put(Schema.AppMetadataTable.Cols.UPSTREAM_VERSION_CODE, upstreamVersionCode);
+        values.put(Schema.AppMetadataTable.Cols.PREFERRED_SIGNER, preferredSigner);
         return Assert.insertApp(context, packageName, appName, values);
     }
 

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

@@ -37,7 +37,7 @@ public class PreferredSignatureTest extends FDroidProviderTest {
     }
 
     private App populateFDroidRepo(Repo repo) {
-        App app = TestUtils.insertApp(context, PACKAGE_NAME, "App", 3100, repo);
+        App app = TestUtils.insertApp(context, PACKAGE_NAME, "App", 3100, repo, TestUtils.UPSTREAM_SIG);
 
         TestUtils.insertApk(context, app, 1100, TestUtils.FDROID_SIG); // 1.0
         TestUtils.insertApk(context, app, 2100, TestUtils.FDROID_SIG); // 2.0
@@ -54,7 +54,7 @@ public class PreferredSignatureTest extends FDroidProviderTest {
     }
 
     private App populateDevRepo(Repo repo) {
-        App app = TestUtils.insertApp(context, PACKAGE_NAME, "App", 4100, repo);
+        App app = TestUtils.insertApp(context, PACKAGE_NAME, "App", 4100, repo, TestUtils.THIRD_PARTY_SIG);
 
         TestUtils.insertApk(context, app, 1001, TestUtils.THIRD_PARTY_SIG); // 1.0-rc2
         TestUtils.insertApk(context, app, 1100, TestUtils.THIRD_PARTY_SIG); // 1.0
@@ -78,7 +78,7 @@ public class PreferredSignatureTest extends FDroidProviderTest {
     }
 
     private App populateUpstreamRepo(Repo repo) {
-        App app = TestUtils.insertApp(context, PACKAGE_NAME, "App", 4100, repo);
+        App app = TestUtils.insertApp(context, PACKAGE_NAME, "App", 4100, repo, TestUtils.UPSTREAM_SIG);
 
         TestUtils.insertApk(context, app, 2100, TestUtils.UPSTREAM_SIG);
         TestUtils.insertApk(context, app, 3100, TestUtils.UPSTREAM_SIG);

app/src/test/java/org/fdroid/fdroid/updater/IndexV1UpdaterTest.java

@@ -263,6 +263,7 @@ public class IndexV1UpdaterTest extends FDroidProviderTest {
                 "installedSig",
                 "installedVersionCode",
                 "installedVersionName",
+                "preferredSigner",
                 "prefs",
                 "TAG",
         };