util: mv create_URI to create_bip21_uri, and small clean-up

electrum/gui/kivy/uix/screens.py

@@ -363,13 +363,13 @@ class ReceiveScreen(CScreen):
         Clock.schedule_once(lambda dt: self.update_qr())
 
     def get_URI(self):
-        from electrum.util import create_URI
+        from electrum.util import create_bip21_uri
         amount = self.screen.amount
         if amount:
             a, u = self.screen.amount.split()
             assert u == self.app.base_unit
             amount = Decimal(a) * pow(10, self.app.decimal_point())
-        return create_URI(self.screen.address, amount, self.screen.message)
+        return create_bip21_uri(self.screen.address, amount, self.screen.message)
 
     @profiler
     def update_qr(self):

electrum/gui/qt/main_window.py

@@ -965,16 +965,18 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         req = self.wallet.receive_requests[addr]
         message = self.wallet.labels.get(addr, '')
         amount = req['amount']
-        URI = util.create_URI(addr, amount, message)
+        extra_query_params = {}
         if req.get('time'):
-            URI += "&time=%d"%req.get('time')
+            extra_query_params['time'] = str(int(req.get('time')))
         if req.get('exp'):
-            URI += "&exp=%d"%req.get('exp')
+            extra_query_params['exp'] = str(int(req.get('exp')))
         if req.get('name') and req.get('sig'):
             sig = bfh(req.get('sig'))
             sig = bitcoin.base_encode(sig, base=58)
-            URI += "&name=" + req['name'] + "&sig="+sig
-        return str(URI)
+            extra_query_params['name'] = req['name']
+            extra_query_params['sig'] = sig
+        uri = util.create_bip21_uri(addr, amount, message, extra_query_params=extra_query_params)
+        return str(uri)
 
 
     def sign_payment_request(self, addr):
@@ -1113,7 +1115,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         amount = self.receive_amount_e.get_amount()
         message = self.receive_message_e.text()
         self.save_request_button.setEnabled((amount is not None) or (message != ""))
-        uri = util.create_URI(addr, amount, message)
+        uri = util.create_bip21_uri(addr, amount, message)
         self.receive_qr.setData(uri)
         if self.qr_window and self.qr_window.isVisible():
             self.qr_window.qrw.setData(uri)

electrum/util.py

@@ -798,17 +798,25 @@ def parse_URI(uri: str, on_pr: Callable=None) -> dict:
     return out
 
 
-def create_URI(addr, amount, message):
+def create_bip21_uri(addr, amount_sat: Optional[int], message: Optional[str],
+                     *, extra_query_params: Optional[dict] = None) -> str:
     from . import bitcoin
     if not bitcoin.is_address(addr):
         return ""
+    if extra_query_params is None:
+        extra_query_params = {}
     query = []
-    if amount:
-        query.append('amount=%s'%format_satoshis_plain(amount))
+    if amount_sat:
+        query.append('amount=%s'%format_satoshis_plain(amount_sat))
     if message:
         query.append('message=%s'%urllib.parse.quote(message))
+    for k, v in extra_query_params.items():
+        if not isinstance(k, str) or k != urllib.parse.quote(k):
+            raise Exception(f"illegal key for URI: {repr(k)}")
+        v = urllib.parse.quote(v)
+        query.append(f"{k}={v}")
     p = urllib.parse.ParseResult(scheme='bitcoin', netloc='', path=addr, params='', query='&'.join(query), fragment='')
-    return urllib.parse.urlunparse(p)
+    return str(urllib.parse.urlunparse(p))
 
 
 # Python bug (http://bugs.python.org/issue1927) causes raw_input