display 'low fee' in tx dialog

gui/kivy/uix/dialogs/tx_dialog.py

@@ -112,7 +112,7 @@ class TxDialog(Factory.Popup):
         if timestamp:
             self.date_str = datetime.fromtimestamp(timestamp).isoformat(' ')[:-3]
         elif exp_n:
-            self.date_str = _('Within %d blocks') % exp_n
+            self.date_str = _('Within %d blocks') % exp_n if exp_n > 0 else _('unknown (low fee)')
         else:
             self.date_str = ''
 

gui/qt/transaction_dialog.py

@@ -203,7 +203,8 @@ class TxDialog(QDialog, MessageBoxMixin):
             self.date_label.setText(_("Date: %s")%time_str)
             self.date_label.show()
         elif exp_n:
-            self.date_label.setText(_('Expected confirmation time: %d blocks'%(exp_n)))
+            text = '%d blocks'%(exp_n) if exp_n > 0 else _('unknown (low fee)')
+            self.date_label.setText(_('Expected confirmation time') + ': ' + text)
             self.date_label.show()
         else:
             self.date_label.hide()

lib/network.py

@@ -353,6 +353,8 @@ class Network(util.DaemonThread):
         import operator
         dist = map(lambda x: (x[0], abs(x[1] - fee_per_kb)), self.fee_estimates.items())
         min_target, min_value = min(dist, key=operator.itemgetter(1))
+        if fee_per_kb < self.fee_estimates.get(25)/2:
+            min_target = -1
         return min_target
 
     def notify(self, key):