From 94b87ac7d1a61648275260f7fd2aa440ac880e8e Mon Sep 17 00:00:00 2001
From: Janus <ysangkok@gmail.com>
Date: Wed, 11 Apr 2018 11:07:30 +0200
Subject: [PATCH] lnbase: do not catch all exceptions, tolerate calculations
 with variables from kwargs

---
 lib/lnbase.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/lnbase.py b/lib/lnbase.py
index cafdb9706..d70fee6ee 100644
--- a/lib/lnbase.py
+++ b/lib/lnbase.py
@@ -97,8 +97,10 @@ def gen_msg(msg_type, **kwargs):
         poslenMap = typ["payload"][k]
         leng = calcexp(poslenMap["length"], lengths)
         try:
-            leng = kwargs[poslenMap["length"]]
-        except:
+            clone = dict(lengths)
+            clone.update(kwargs)
+            leng = calcexp(poslenMap["length"], clone)
+        except KeyError:
             pass
         try:
             param = kwargs[k]
@@ -106,7 +108,7 @@ def gen_msg(msg_type, **kwargs):
             param = 0
         try:
             param = param.to_bytes(length=leng, byteorder="big")
-        except:
+        except ValueError:
             raise Exception("{} does not fit in {} bytes".format(k, leng))
         lengths[k] = len(param)
         data += param