When calibre does a conversion from the same format to the same format, for

example, from EPUB to EPUB, the original file is saved, so that in case the
conversion is poor, you can tweak the settings and run it again. The orignal is automatically used every time you re-run the conversion. If you want the old behavior, there is a tweak that prevents calibre from saving the originals in Preferences->Tweaks.

resources/default_tweaks.py

@@ -366,3 +366,10 @@ server_listen_on = '0.0.0.0'
 # on at your own risk!
 unified_title_toolbar_on_osx = False
 
+#: Save original file when converting from same format to same format
+# When calibre does a conversion from the same format to the same format, for
+# example, from EPUB to EPUB, the original file is saved, so that in case the
+# conversion is poor, you can tweak the settings and run it again. By setting
+# this to False you can prevent calibre from saving the original file.
+save_original_format = True
+

src/calibre/ebooks/conversion/plumber.py

@@ -602,7 +602,7 @@ OptionRecommendation(name='sr3_replace',
         input_fmt = os.path.splitext(self.input)[1]
         if not input_fmt:
             raise ValueError('Input file must have an extension')
-        input_fmt = input_fmt[1:].lower()
+        input_fmt = input_fmt[1:].lower().replace('original_', '')
         self.archive_input_tdir = None
         if input_fmt in ARCHIVE_FMTS:
             self.log('Processing archive...')

src/calibre/ebooks/oeb/iterator.py

@@ -92,7 +92,7 @@ class EbookIterator(object):
         self.config = DynamicConfig(name='iterator')
         ext = os.path.splitext(pathtoebook)[1].replace('.', '').lower()
         ext = re.sub(r'(x{0,1})htm(l{0,1})', 'html', ext)
-        self.ebook_ext = ext
+        self.ebook_ext = ext.replace('original_', '')
 
     def search(self, text, index, backwards=False):
         text = text.lower()

src/calibre/gui2/actions/convert.py

@@ -12,7 +12,7 @@ from PyQt4.Qt import QModelIndex, QMenu
 
 from calibre.gui2 import error_dialog, Dispatcher
 from calibre.gui2.tools import convert_single_ebook, convert_bulk_ebook
-from calibre.utils.config import prefs
+from calibre.utils.config import prefs, tweaks
 from calibre.gui2.actions import InterfaceAction
 from calibre.customize.ui import plugin_for_input_format
 
@@ -118,6 +118,8 @@ class ConvertAction(InterfaceAction):
     def queue_convert_jobs(self, jobs, changed, bad, rows, previous,
             converted_func, extra_job_args=[]):
         for func, args, desc, fmt, id, temp_files in jobs:
+            func, _, same_fmt = func.partition(':')
+            same_fmt = same_fmt == 'same_fmt'
             input_file = args[0]
             input_fmt = os.path.splitext(input_file)[1]
             core_usage = 1
@@ -131,6 +133,7 @@ class ConvertAction(InterfaceAction):
                 job = self.gui.job_manager.run_job(Dispatcher(converted_func),
                                             func, args=args, description=desc,
                                             core_usage=core_usage)
+                job.conversion_of_same_fmt = same_fmt
                 args = [temp_files, fmt, id]+extra_job_args
                 self.conversion_jobs[job] = tuple(args)
 
@@ -166,14 +169,18 @@ class ConvertAction(InterfaceAction):
             if job.failed:
                 self.gui.job_exception(job)
                 return
+            same_fmt = getattr(job, 'conversion_of_same_fmt', False)
             fmtf = temp_files[-1].name
             if os.stat(fmtf).st_size < 1:
                 raise Exception(_('Empty output file, '
                     'probably the conversion process crashed'))
 
+            db = self.gui.current_db
+            if same_fmt and tweaks['save_original_format']:
+                db.save_original_format(book_id, fmt, notify=False)
+
             with open(temp_files[-1].name, 'rb') as data:
-                self.gui.library_view.model().db.add_format(book_id, \
+                db.add_format(book_id, fmt, data, index_is_id=True)
-                    fmt, data, index_is_id=True)
             self.gui.status_bar.show_message(job.description + \
                     (' completed'), 2000)
         finally:

src/calibre/gui2/actions/view.py

@@ -128,7 +128,8 @@ class ViewAction(InterfaceAction):
             self.gui.unsetCursor()
 
     def _view_file(self, name):
-        ext = os.path.splitext(name)[1].upper().replace('.', '')
+        ext = os.path.splitext(name)[1].upper().replace('.',
+                '').replace('ORIGINAL_', '')
         viewer = 'lrfviewer' if ext == 'LRF' else 'ebook-viewer'
         internal = ext in config['internally_viewed_formats']
         self._launch_viewer(name, viewer, internal)

src/calibre/gui2/tools.py

@@ -53,7 +53,9 @@ def convert_single_ebook(parent, db, book_ids, auto_conversion=False, # {{{
                 mi = db.get_metadata(book_id, True)
                 in_file = PersistentTemporaryFile('.'+d.input_format)
                 with in_file:
-                    db.copy_format_to(book_id, d.input_format, in_file,
+                    input_fmt = db.original_fmt(book_id, d.input_format).lower()
+                    same_fmt = input_fmt == d.output_format.lower()
+                    db.copy_format_to(book_id, input_fmt, in_file,
                             index_is_id=True)
 
                 out_file = PersistentTemporaryFile('.' + d.output_format)
@@ -79,7 +81,10 @@ def convert_single_ebook(parent, db, book_ids, auto_conversion=False, # {{{
                     temp_files.append(d.cover_file)
                 args = [in_file.name, out_file.name, recs]
                 temp_files.append(out_file)
-                jobs.append(('gui_convert_override', args, desc, d.output_format.upper(), book_id, temp_files))
+                func = 'gui_convert_override'
+                if same_fmt:
+                    func += ':same_fmt'
+                jobs.append((func, args, desc, d.output_format.upper(), book_id, temp_files))
 
                 changed = True
                 d.break_cycles()
@@ -144,10 +149,12 @@ class QueueBulk(QProgressDialog):
 
         try:
             input_format = get_input_format_for_book(self.db, book_id, None)[0]
+            input_fmt = self.db.original_fmt(book_id, input_format).lower()
+            same_fmt = input_fmt == self.output_format.lower()
             mi, opf_file = create_opf_file(self.db, book_id)
             in_file = PersistentTemporaryFile('.'+input_format)
             with in_file:
-                self.db.copy_format_to(book_id, input_format, in_file,
+                self.db.copy_format_to(book_id, input_fmt, in_file,
                         index_is_id=True)
 
             out_file = PersistentTemporaryFile('.' + self.output_format)
@@ -192,7 +199,10 @@ class QueueBulk(QProgressDialog):
 
             args = [in_file.name, out_file.name, lrecs]
             temp_files.append(out_file)
-            self.jobs.append(('gui_convert_override', args, desc, self.output_format.upper(), book_id, temp_files))
+            func = 'gui_convert_override'
+            if same_fmt:
+                func += ':same_fmt'
+            self.jobs.append((func, args, desc, self.output_format.upper(), book_id, temp_files))
 
             self.changed = True
             self.setValue(self.i)

src/calibre/gui2/viewer/main.py

@@ -661,6 +661,7 @@ class EbookViewer(MainWindow, Ui_EbookViewer):
     def save_current_position(self):
         if not self.get_remember_current_page_opt():
             return
+        if hasattr(self, 'current_index'):
             try:
                 pos = self.view.bookmark()
                 bookmark = '%d#%s'%(self.current_index, pos)

src/calibre/library/database2.py

@@ -1312,6 +1312,23 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             self.notify('metadata', [id])
         return True
 
+    def save_original_format(self, book_id, fmt, notify=True):
+        fmt = fmt.upper()
+        if 'ORIGINAL' in fmt:
+            raise ValueError('Cannot save original of an original fmt')
+        opath = self.format_abspath(book_id, fmt, index_is_id=True)
+        if opath is None:
+            return False
+        nfmt = 'ORIGINAL_'+fmt
+        with lopen(opath, 'rb') as f:
+            return self.add_format(book_id, nfmt, f, index_is_id=True, notify=notify)
+
+    def original_fmt(self, book_id, fmt):
+        fmt = fmt
+        nfmt = ('ORIGINAL_%s'%fmt).upper()
+        opath = self.format_abspath(book_id, nfmt, index_is_id=True)
+        return fmt if opath is None else nfmt
+
     def delete_book(self, id, notify=True, commit=True, permanent=False):
         '''
         Removes book from the result cache and the underlying database.