return bytes in scan_barcode

gui/qt/main_window.py

@@ -2056,14 +2056,11 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         if not data:
             return
         # if the user scanned a bitcoin URI
-        if data.startswith("bitcoin:"):
+        if str(data).startswith("bitcoin:"):
             self.pay_to_URI(data)
             return
         # else if the user scanned an offline signed tx
-        # transactions are binary, but qrcode seems to return utf-8...
-        data = data.decode('utf-8')
-        z = bitcoin.base_decode(data, length=None, base=43)
-        data = bh2u(''.join(chr(ord(b)) for b in z))
+        data = bh2u(bitcoin.base_decode(data, length=None, base=43))
         tx = self.tx_from_text(data)
         if not tx:
             return

gui/qt/qrtextedit.py

@@ -61,8 +61,7 @@ class ScanQRTextEdit(ButtonsTextEdit, MessageBoxMixin):
         except BaseException as e:
             self.show_error(str(e))
             data = ''
-        if type(data) != str:
-            data = ''
+        data = str(data)
         self.setText(data)
         return data
 

lib/qrscanner.py

@@ -62,7 +62,7 @@ def scan_barcode(device='', timeout=-1, display=True, threaded=False):
         return
     symbol = libzbar.zbar_symbol_set_first_symbol(symbols)
     data = libzbar.zbar_symbol_get_data(symbol)
-    return str(data)
+    return data
 
 def _find_system_cameras():
     device_root = "/sys/class/video4linux"