Issue #25510: fileinput.FileInput.readline() now returns b'' instead of ''

at the end if the FileInput was opened with binary mode.
Patch by Ryosuke Ito.

diff --cc Lib/fileinput.py
Simple merge

diff --cc Misc/NEWS
index a8a1f3170a2ee142d2c93b8ff17c014b396c5836,fb7dcd3c05c6a5f3222fae727f407de4748501d8..20b1ae42e05d48d81faa60e3b0d4b2b9c0909910
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -48,11 -96,10 +48,15 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #25510: fileinput.FileInput.readline() now returns b'' instead of ''
+   at the end if the FileInput was opened with binary mode.
+   Patch by Ryosuke Ito.
+ 
 +- Issue #25503: Fixed inspect.getdoc() for inherited docstrings of properties.
 +  Original patch by John Mark Vandenberg.
 +
 +- Issue #25515: Always use os.urandom as a source of randomness in uuid.uuid4.
 +
  - Issue #21827: Fixed textwrap.dedent() for the case when largest common
    whitespace is a substring of smallest leading whitespace.
    Based on patch by Robert Li.