From 21c84615dea4e4b4b44760ff60212f03fcb4c727 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 3 May 2012 17:56:20 +0530
Subject: [PATCH] CHM Input: Handle files with deeply nested markup and non
 html files listed at the start of the manifest. Fixes #993607 (chm to mobi
 conversion crashes with "maximum recursion depth exceeded")

---
 src/calibre/ebooks/chm/reader.py | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/calibre/ebooks/chm/reader.py b/src/calibre/ebooks/chm/reader.py
index fc7d865265..056b180fd3 100644
--- a/src/calibre/ebooks/chm/reader.py
+++ b/src/calibre/ebooks/chm/reader.py
@@ -155,7 +155,10 @@ class CHMReader(CHMFile):
                     self.hhc_path = f
                     break
         if self.hhc_path not in files and files:
-            self.hhc_path = files[0]
+            for f in files:
+                if f.partition('.')[-1].lower() in {'html', 'htm'}:
+                    self.hhc_path = f
+                    break
 
         if self.hhc_path == '.hhc' and self.hhc_path not in files:
             from calibre import walk
@@ -241,7 +244,10 @@ class CHMReader(CHMFile):
         except:
             pass
         # do not prettify, it would reformat the <pre> tags!
-        return str(soup)
+        try:
+            return str(soup)
+        except RuntimeError:
+            return data
 
     def Contents(self):
         if self._contents is not None: