Hide keep alive option

app/src/main/java/eu/faircode/email/ApplicationEx.java

@@ -89,15 +89,6 @@ public class ApplicationEx extends Application implements SharedPreferences.OnSh
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
         final boolean crash_reports = prefs.getBoolean("crash_reports", false);
 
-        try {
-            boolean tcp_keep_alive = prefs.getBoolean("tcp_keep_alive", false);
-            System.setProperty("fairemail.tcp_keep_alive", Boolean.toString(tcp_keep_alive));
-        } catch (Throwable ex) {
-            Log.e(ex);
-        }
-
-        prefs.registerOnSharedPreferenceChangeListener(this);
-
         prev = Thread.getDefaultUncaughtExceptionHandler();
 
         Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
@@ -123,6 +114,15 @@ public class ApplicationEx extends Application implements SharedPreferences.OnSh
 
         upgrade(this);
 
+        try {
+            boolean tcp_keep_alive = prefs.getBoolean("tcp_keep_alive", false);
+            System.setProperty("fairemail.tcp_keep_alive", Boolean.toString(tcp_keep_alive));
+        } catch (Throwable ex) {
+            Log.e(ex);
+        }
+
+        prefs.registerOnSharedPreferenceChangeListener(this);
+
         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O)
             NotificationHelper.createNotificationChannels(this);
 
@@ -384,6 +384,8 @@ public class ApplicationEx extends Application implements SharedPreferences.OnSh
                 editor.putBoolean("beige", false);
         } else if (version < 1385)
             editor.remove("parse_classes");
+        else if (version < 1401)
+            editor.remove("tcp_keep_alive");
 
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && !BuildConfig.DEBUG)
             editor.remove("background_service");

app/src/main/java/eu/faircode/email/FragmentOptionsConnection.java

@@ -62,6 +62,7 @@ public class FragmentOptionsConnection extends FragmentBase implements SharedPre
     private EditText etTimeout;
     private SwitchCompat swPreferIp4;
     private SwitchCompat swTcpKeepAlive;
+    private TextView tvTcpKeepAliveHint;
     private SwitchCompat swSslHarden;
     private Button btnManage;
     private TextView tvNetworkMetered;
@@ -89,6 +90,7 @@ public class FragmentOptionsConnection extends FragmentBase implements SharedPre
         etTimeout = view.findViewById(R.id.etTimeout);
         swPreferIp4 = view.findViewById(R.id.swPreferIp4);
         swTcpKeepAlive = view.findViewById(R.id.swTcpKeepAlive);
+        tvTcpKeepAliveHint = view.findViewById(R.id.tvTcpKeepAliveHint);
         swSslHarden = view.findViewById(R.id.swSslHarden);
         btnManage = view.findViewById(R.id.btnManage);
 
@@ -168,6 +170,10 @@ public class FragmentOptionsConnection extends FragmentBase implements SharedPre
             }
         });
 
+        boolean debug = prefs.getBoolean("debug", false);
+        swTcpKeepAlive.setVisibility(debug || BuildConfig.DEBUG ? View.VISIBLE : View.GONE);
+        tvTcpKeepAliveHint.setVisibility(debug || BuildConfig.DEBUG ? View.VISIBLE : View.GONE);
+
         swTcpKeepAlive.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {