From 8ab61a3a0a470237f61f65c9a5e5bf2bfdfcd9d5 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 26 Apr 2010 09:26:57 -0600
Subject: [PATCH] Fix #5379 (ebook-convert rename a png image cover to jpg)

---
 src/calibre/ebooks/conversion/plumber.py      |  5 ++++-
 src/calibre/ebooks/oeb/transforms/metadata.py | 14 ++++++++------
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/calibre/ebooks/conversion/plumber.py b/src/calibre/ebooks/conversion/plumber.py
index ec14fb6cfb..55a853f1d2 100644
--- a/src/calibre/ebooks/conversion/plumber.py
+++ b/src/calibre/ebooks/conversion/plumber.py
@@ -676,7 +676,10 @@ OptionRecommendation(name='timestamp',
         if mi.cover:
             if mi.cover.startswith('http:') or mi.cover.startswith('https:'):
                 mi.cover = self.download_cover(mi.cover)
-            mi.cover_data = ('', open(mi.cover, 'rb').read())
+            ext = mi.cover.rpartition('.')[-1].lower().strip()
+            if ext not in ('png', 'jpg', 'jpeg'):
+                ext = 'jpg'
+            mi.cover_data = (ext, open(mi.cover, 'rb').read())
             mi.cover = None
         self.user_metadata = mi
 
diff --git a/src/calibre/ebooks/oeb/transforms/metadata.py b/src/calibre/ebooks/oeb/transforms/metadata.py
index 97bad07a58..22a89f5a47 100644
--- a/src/calibre/ebooks/oeb/transforms/metadata.py
+++ b/src/calibre/ebooks/oeb/transforms/metadata.py
@@ -8,6 +8,7 @@ __docformat__ = 'restructuredtext en'
 
 import os
 from calibre.utils.date import isoformat, now
+from calibre import guess_type
 
 def meta_info_to_oeb_metadata(mi, m, log):
     from calibre.ebooks.oeb.base import OPF
@@ -92,15 +93,16 @@ class MergeMetadata(object):
                                     scheme='uuid')
             self.oeb.uid = self.oeb.metadata.identifier[-1]
 
-
-
-
     def set_cover(self, mi, prefer_metadata_cover):
-        cdata = ''
+        cdata, ext = '', 'jpg'
         if mi.cover and os.access(mi.cover, os.R_OK):
             cdata = open(mi.cover, 'rb').read()
+            ext = mi.cover.rpartition('.')[-1].lower().strip()
         elif mi.cover_data and mi.cover_data[-1]:
             cdata = mi.cover_data[1]
+            ext = mi.cover_data[0]
+        if ext not in ('png', 'jpg', 'jpeg'):
+            ext = 'jpg'
         id = old_cover = None
         if 'cover' in self.oeb.guide:
             old_cover = self.oeb.guide['cover']
@@ -120,8 +122,8 @@ class MergeMetadata(object):
                 self.oeb.manifest.add(id, old_cover.href, 'image/jpeg')
                 return id
         if cdata:
-            id, href = self.oeb.manifest.generate('cover', 'cover.jpg')
-            self.oeb.manifest.add(id, href, 'image/jpeg', data=cdata)
+            id, href = self.oeb.manifest.generate('cover', 'cover.'+ext)
+            self.oeb.manifest.add(id, href, guess_type('cover.'+ext)[0], data=cdata)
             self.oeb.guide.add('cover', 'Cover', href)
         return id