SONY XML cache: Handle case where XML db contains reference to a file that does not exist gracefully

src/calibre/devices/prs505/sony_cache.py

@@ -610,7 +610,11 @@ class XMLCache(object):
         # is not new, compare its Sony DB date against localtime and gmtime.
         # Count the matches. When we must set a date, use the one with the most
         # matches. Use localtime if the case of a tie, and hope it is right.
+        try:
             timestamp = os.path.getmtime(path)
+        except:
+            debug_print('Failed to get timestamp for:', path)
+            timestamp = time.time()
         rec_date = record.get('date', None)
 
         def clean(x):
@@ -646,7 +650,10 @@ class XMLCache(object):
                 debug_print("Use GMT TZ for new book", book.lpath)
             date = strftime(timestamp, zone=tz)
             record.set('date', clean(date))
+        try:
             record.set('size', clean(str(os.stat(path).st_size)))
+        except:
+            record.set('size', '0')
         title = book.title if book.title else _('Unknown')
         record_set('title', title)
         ts = book.title_sort