IGN:Proper error messages when mimagemagick fails to load. Also workaround occasional IOError when sendingfiles to devices on linux

src/calibre/devices/usbms/cli.py

@@ -24,6 +24,12 @@ class File(object):
         self.name = os.path.basename(path)
 
 
+def check_transfer(infile, dest):
+    infile.seek(0)
+    dest.seek(0)
+    return infile.read() == dest.read()
+
+
 class CLI(object):
 
     def get_file(self, path, outfile, end_session=True):
@@ -45,7 +51,15 @@ class CLI(object):
         if not os.path.exists(d):
             os.makedirs(d)
         with open(path, 'wb') as dest:
-            shutil.copyfileobj(infile, dest)
+            try:
+                shutil.copyfileobj(infile, dest)
+            except IOError:
+                print 'WARNING: First attempt to send file to device failed'
+                infile.seek(0)
+                dest.seek(0)
+                dest.truncate()
+                shutil.copyfileobj(infile, dest)
+            #if not check_transfer(infile, dest): raise Exception('Transfer failed')
         if close:
             infile.close()
 

src/calibre/utils/PythonMagickWand.py

@@ -87,7 +87,8 @@ _magick = _magick_error = None
 try:
     _magick = ctypes.CDLL(_lib)
 except Exception, err:
-    _magick_erorr = str(err)
+    global _magick_error
+    _magick_error = str(err)
 
 _initialized = False
 def initialize():
@@ -4362,7 +4363,6 @@ except AttributeError,e:
 else:
     PixelSetColor = _magick.PixelSetColor
 
-
 if __name__=='__main__':
     import doctest
     doctest.testmod()