From 1fc70273959c956ab410166dda673561613cf691 Mon Sep 17 00:00:00 2001
From: Lu Wang <coolwanglu@gmail.com>
Date: Mon, 1 Jul 2013 12:01:29 +0800
Subject: [PATCH] check if em size is 0

---
 src/HTMLState.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/HTMLState.h b/src/HTMLState.h
index b705068..060bfdd 100644
--- a/src/HTMLState.h
+++ b/src/HTMLState.h
@@ -34,8 +34,10 @@ struct HTMLTextState
     
     // the offset cause by a single ' ' char
     double single_space_offset(void) const {
-        assert(font_info->em_size != 0);
-        return word_space + letter_space + font_info->space_width / font_info->em_size * font_size;
+        double offset = word_space + letter_space;
+        if(font_info->em_size != 0)
+            offset += font_info->space_width / font_info->em_size * font_size;
+        return offset;
     }
     // calculate em_size of this state
     double em_size(void) const {