From f1ba77d1725212864d14091eab0e9e741fa7d9e2 Mon Sep 17 00:00:00 2001
From: "Marshall T. Vandegrift" <llasram@gmail.com>
Date: Tue, 24 Feb 2009 23:43:54 -0500
Subject: [PATCH] Fix #1886. Handle invalid non-numeric font-size values.

---
 src/calibre/ebooks/oeb/transforms/flatcss.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/calibre/ebooks/oeb/transforms/flatcss.py b/src/calibre/ebooks/oeb/transforms/flatcss.py
index ee7d7fa0b2..63466ac551 100644
--- a/src/calibre/ebooks/oeb/transforms/flatcss.py
+++ b/src/calibre/ebooks/oeb/transforms/flatcss.py
@@ -37,6 +37,8 @@ class KeyMapper(object):
 
     @staticmethod
     def relate(size, base):
+        if size == 0:
+            return base
         size = float(size)
         base = float(base)
         if abs(size - base) < 0.1: return 0
@@ -48,6 +50,7 @@ class KeyMapper(object):
         return result
         
     def __getitem__(self, ssize):
+        ssize = asfloat(ssize, 0)
         if ssize in self.cache:
             return self.cache[ssize]
         dsize = self.map(ssize)
@@ -66,6 +69,7 @@ class ScaleMapper(object):
         self.dscale = float(dbase) / float(sbase)
 
     def __getitem__(self, ssize):
+        ssize = asfloat(ssize, 0)
         dsize = ssize * self.dscale
         return dsize