From 5840b60967f54bcb5dc8fc3d12ed52c760b4298d Mon Sep 17 00:00:00 2001
From: Florian Bruhin <me@the-compiler.org>
Date: Tue, 16 Oct 2018 12:29:49 +0200
Subject: [PATCH] Fix utils.ceil_log with invalid log values

---
 qutebrowser/utils/utils.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/qutebrowser/utils/utils.py b/qutebrowser/utils/utils.py
index a6c8e866c..6119675ba 100644
--- a/qutebrowser/utils/utils.py
+++ b/qutebrowser/utils/utils.py
@@ -719,6 +719,8 @@ def ceil_log(number, base):
 
     Use only integer arithmetic in order to avoid numerical error.
     """
+    if number < 1 or base < 2:
+        raise ValueError("math domain error")
     result = 1
     accum = base
     while accum < number: