From 7ac3ff293e3ed719bdde0c36ad938b386f117d60 Mon Sep 17 00:00:00 2001
From: Chirayu Desai <chirayudesai1@gmail.com>
Date: Tue, 18 Apr 2017 17:21:18 +0530
Subject: [PATCH] Don't allow uninstalling system apps.

* F-Droid cannnot uninstall system apps, only their updates,
  but even with the privileged extension, that can get complicated.
* Let's just not allow uninstalling system apps, the phone's settings
  app can happily disable/re-enable system apps, and also uninstalls
  their updates on disabling.
---
 .../main/java/org/fdroid/fdroid/data/App.java | 21 +++++++++++++++++++
 .../fdroid/installer/InstallerFactory.java    |  2 +-
 .../views/AppDetailsRecyclerViewAdapter.java  |  2 +-
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/app/src/main/java/org/fdroid/fdroid/data/App.java b/app/src/main/java/org/fdroid/fdroid/data/App.java
index 66d4009e9..ad189b7b0 100644
--- a/app/src/main/java/org/fdroid/fdroid/data/App.java
+++ b/app/src/main/java/org/fdroid/fdroid/data/App.java
@@ -960,6 +960,27 @@ public class App extends ValueObject implements Comparable<App>, Parcelable {
         return 0;
     }
 
+    /**
+     * System apps aren't uninstallable, only their updates are.
+     */
+    public boolean isUninstallable(Context context) {
+        if (this.isInstalled()) {
+            PackageManager pm = context.getPackageManager();
+            ApplicationInfo appInfo;
+            try {
+                appInfo = pm.getApplicationInfo(this.packageName,
+                        PackageManager.GET_UNINSTALLED_PACKAGES);
+            } catch (PackageManager.NameNotFoundException e) {
+                return false;
+            }
+
+            final boolean isSystem = (appInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
+            return !isSystem && this.isInstalled();
+        } else {
+            return false;
+        }
+    }
+
     @Override
     public void writeToParcel(Parcel dest, int flags) {
         dest.writeByte(this.compatible ? (byte) 1 : (byte) 0);
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java b/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java
index e00206d17..066cec1d3 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/InstallerFactory.java
@@ -47,7 +47,7 @@ public class InstallerFactory {
 
 
         Installer installer;
-        if (!apk.apkName.endsWith(".apk")) {
+        if (apk.apkName != null && !apk.apkName.endsWith(".apk")) {
             String msg = context.getString(R.string.install_error_not_yet_supported, apk.apkName);
             Toast.makeText(context, msg, Toast.LENGTH_LONG).show();
             Utils.debugLog(TAG, msg);
diff --git a/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java b/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java
index d4061d835..26b758c21 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java
@@ -469,7 +469,7 @@ public class AppDetailsRecyclerViewAdapter
             }
             updateAntiFeaturesWarning();
             buttonSecondaryView.setText(R.string.menu_uninstall);
-            buttonSecondaryView.setVisibility(app.isInstalled() ? View.VISIBLE : View.INVISIBLE);
+            buttonSecondaryView.setVisibility(app.isUninstallable(context) ? View.VISIBLE : View.INVISIBLE);
             buttonSecondaryView.setOnClickListener(onUnInstallClickListener);
             buttonPrimaryView.setText(R.string.menu_install);
             buttonPrimaryView.setVisibility(versions.size() > 0 ? View.VISIBLE : View.GONE);