From 2fab6814442ee843ab1271d2c83a873c1ea4b6f4 Mon Sep 17 00:00:00 2001
From: SomberNight <somber.night@protonmail.com>
Date: Mon, 2 Mar 2020 19:32:53 +0100
Subject: [PATCH] bolt11 invoice: strip (and so accept with) leading/trailing
 whitespaces

---
 electrum/util.py | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/electrum/util.py b/electrum/util.py
index 7268741ac..e6a99c1d0 100644
--- a/electrum/util.py
+++ b/electrum/util.py
@@ -930,11 +930,12 @@ def create_bip21_uri(addr, amount_sat: Optional[int], message: Optional[str],
 
 
 def maybe_extract_bolt11_invoice(data: str) -> Optional[str]:
-    lower = data.lower()
-    if lower.startswith('lightning:ln'):
-        lower = lower[10:]
-    if lower.startswith('ln'):
-        return lower
+    data = data.strip()  # whitespaces
+    data = data.lower()
+    if data.startswith('lightning:ln'):
+        data = data[10:]
+    if data.startswith('ln'):
+        return data
     return None