EPUB metadata: When setting a cover image for an EPUB file that has no cover image defined, add the new cover image instead of aborting.

Note that this is not a full EPUB cover, for that you still have to
convert/use book polishing. However, this limited support should at
least allow the cover image to work with those applications that support
the EPUB raster cover metadata standard.

src/calibre/ebooks/metadata/epub.py

@@ -276,7 +276,7 @@ def set_metadata(stream, mi, apply_null=False, update_timestamp=False, force_ide
             pass
 
     opfbytes, ver, raster_cover = set_metadata_opf(
-        reader.read_bytes(reader.opf_path), mi,
+        reader.read_bytes(reader.opf_path), posixpath.dirname(reader.opf_path), mi,
         cover_data=new_cdata, apply_null=apply_null, update_timestamp=update_timestamp, force_identifiers=force_identifiers)
     cpath = None
     replacements = {}
@@ -294,10 +294,10 @@ def set_metadata(stream, mi, apply_null=False, update_timestamp=False, force_ide
 
     if isinstance(reader.archive, LocalZipFile):
         reader.archive.safe_replace(reader.container[OPF.MIMETYPE], opfbytes,
-            extra_replacements=replacements)
+            extra_replacements=replacements, add_missing=True)
     else:
         safe_replace(stream, reader.container[OPF.MIMETYPE], opfbytes,
-            extra_replacements=replacements)
+            extra_replacements=replacements, add_missing=True)
     try:
         if cpath is not None:
             replacements[cpath].close()

src/calibre/ebooks/metadata/opf.py

@@ -6,8 +6,8 @@ from __future__ import (unicode_literals, division, absolute_import,
                         print_function)
 
 from calibre.ebooks.metadata import parse_opf_version
-from calibre.ebooks.metadata.opf2 import OPF
-from calibre.ebooks.metadata.utils import parse_opf, normalize_languages
+from calibre.ebooks.metadata.opf2 import OPF, pretty_print
+from calibre.ebooks.metadata.utils import parse_opf, normalize_languages, create_manifest_item
 from calibre.ebooks.metadata import MetaInformation
 
 class DummyFile(object):
@@ -26,7 +26,7 @@ def get_metadata(stream):
     opf = OPF(None, preparsed_opf=root, read_toc=False)
     return opf.to_book_metadata(), ver, opf.raster_cover, opf.first_spine_item()
 
-def set_metadata_opf2(root, mi, cover_data=None, apply_null=False, update_timestamp=False, force_identifiers=False):
+def set_metadata_opf2(root, cover_prefix, mi, opf_version, cover_data=None, apply_null=False, update_timestamp=False, force_identifiers=False):
     mi = MetaInformation(mi)
     for x in ('guide', 'toc', 'manifest', 'spine'):
         setattr(mi, x, None)
@@ -45,13 +45,29 @@ def set_metadata_opf2(root, mi, cover_data=None, apply_null=False, update_timest
         opf.set_identifiers({k:v for k, v in orig.iteritems() if k and v})
     if update_timestamp and mi.timestamp is not None:
         opf.timestamp = mi.timestamp
-    return opf.render(), opf.raster_cover
+    raster_cover = opf.raster_cover
+    if raster_cover is None and cover_data is not None:
+        if cover_prefix and not cover_prefix.endswith('/'):
+            cover_prefix += '/'
+        name = cover_prefix + 'cover.jpg'
+        i = create_manifest_item(opf.root, name, 'cover')
+        if i is not None:
+            if opf_version.major < 3:
+                [x.getparent().remove(x) for x in opf.root.xpath('//*[local-name()="meta" and @name="cover"]')]
+                m = opf.create_metadata_element('meta', is_dc=False)
+                m.set('name', 'cover'), m.set('content', i.get('id'))
+            else:
+                i.set('properties', 'cover-image')
+            raster_cover = name
 
-def set_metadata(stream, mi, cover_data=None, apply_null=False, update_timestamp=False, force_identifiers=False):
+    with pretty_print:
+        return opf.render(), raster_cover
+
+def set_metadata(stream, cover_prefix, mi, cover_data=None, apply_null=False, update_timestamp=False, force_identifiers=False):
     if isinstance(stream, bytes):
         stream = DummyFile(stream)
     root = parse_opf(stream)
     ver = parse_opf_version(root.get('version'))
     opfbytes, raster_cover = set_metadata_opf2(
-        root, mi, cover_data=cover_data, apply_null=apply_null, update_timestamp=update_timestamp, force_identifiers=force_identifiers)
+        root, cover_prefix, mi, ver, cover_data=cover_data, apply_null=apply_null, update_timestamp=update_timestamp, force_identifiers=force_identifiers)
     return opfbytes, ver, raster_cover

src/calibre/ebooks/metadata/opf2.py

@@ -1172,7 +1172,8 @@ class OPF(object):  # {{{
                         return item.get('href', None)
         elif self.package_version >= 3.0:
             for item in self.itermanifest():
-                if item.get('properties') == 'cover-image':
+                props = set((item.get('properties') or '').lower().split())
+                if 'cover-image' in props:
                     mt = item.get('media-type', '')
                     if mt and 'xml' not in mt and 'html' not in mt:
                         return item.get('href', None)

src/calibre/ebooks/metadata/utils.py

@@ -9,6 +9,8 @@ from future_builtins import map
 from lxml import etree
 
 from calibre.ebooks.chardet import xml_to_unicode
+from calibre.ebooks.oeb.base import OPF
+from calibre.ebooks.oeb.polish.utils import guess_type
 from calibre.spell import parse_lang_code
 from calibre.utils.localization import lang_as_iso639_1
 
@@ -48,3 +50,26 @@ def normalize_languages(opf_languages, mi_languages):
         return lc
     return list(map(norm, mi_languages))
 
+def ensure_unique(template, existing):
+    b, e = template.rpartition('.')[::2]
+    if e:
+        e = '.' + e
+    q = template
+    c = 0
+    while q in existing:
+        c += 1
+        q = '%s-%d%s' % (b, c, e)
+    return q
+
+def create_manifest_item(root, href_template, id_template, media_type=None):
+    all_ids = frozenset(root.xpath('//*/@id'))
+    all_hrefs = frozenset(root.xpath('//*/@href'))
+    href = ensure_unique(href_template, all_hrefs)
+    item_id = ensure_unique(id_template, all_ids)
+    manifest = root.find(OPF('manifest'))
+    if manifest is not None:
+        i = manifest.makeelement(OPF('item'))
+        i.set('href', href), i.set('id', item_id)
+        i.set('media-type', media_type or guess_type(href_template))
+        manifest.append(i)
+        return i