Fix #3448 (Problems loading HTML files in v6.11)

src/calibre/ebooks/html/input.py

@@ -262,9 +262,9 @@ class HTMLInput(InputFormatPlugin):
                 )
         ),
 
-        OptionRecommendation(name='unwrap_factor', recommended_value=0.5,
+        OptionRecommendation(name='unwrap_factor', recommended_value=None,
             help=_('Average line length for line breaking if the HTML is from a '
-                'previous partial conversion of a PDF file.')),
+                'previous partial conversion of a PDF file. Default is %default.')),
 
     ])
 

src/calibre/ebooks/oeb/base.py

@@ -773,6 +773,7 @@ class Manifest(object):
             data = self.oeb.decode(data)
             data = self.oeb.html_preprocessor(data)
 
+
             # Remove DOCTYPE declaration as it messes up parsing
             # Inparticular it causes tostring to insert xmlns
             # declarations, which messes up the coercing logic

src/calibre/library/cli.py

@@ -98,9 +98,10 @@ STANZA_TEMPLATE='''\
 '''
 
 def send_message(msg=''):
+    prints('Notifying calibre of the change')
     from calibre.utils.ipc import RC
     import time
-    t = RC()
+    t = RC(print_error=False)
     t.start()
     time.sleep(3)
     if t.done:

src/calibre/utils/ipc/__init__.py

@@ -16,10 +16,20 @@ ADDRESS = r'\\.\pipe\CalibreGUI' if iswindows else \
 
 class RC(Thread):
 
+    def __init__(self, print_error=True):
+        self.print_error = print_error
+        Thread.__init__(self)
+        self.conn = None
+
     def run(self):
         from multiprocessing.connection import Client
         self.done = False
-        self.conn = Client(ADDRESS)
-        self.done = True
+        try:
+            self.conn = Client(ADDRESS)
+            self.done = True
+        except:
+            if self.print_error:
+                import traceback
+                traceback.print_exc()