Issue #29319: Prevent RunMainFromImporter overwriting sys.path[0].

1 files changed, 2 insertions, 3 deletions

diff --git a/Lib/base64.py b/Lib/base64.py
index adaec1de61..58f6ad6816 100755
--- a/Lib/base64.py
+++ b/Lib/base64.py
@@ -55,8 +55,7 @@ def b64encode(s, altchars=None):
     alternative alphabet for the '+' and '/' characters.  This allows an
     application to e.g. generate url or filesystem safe Base64 strings.
     """
-    # Strip off the trailing newline
-    encoded = binascii.b2a_base64(s)[:-1]
+    encoded = binascii.b2a_base64(s, newline=False)
     if altchars is not None:
         assert len(altchars) == 2, repr(altchars)
         return encoded.translate(bytes.maketrans(b'+/', altchars))
@@ -156,7 +155,7 @@ def b32encode(s):
     leftover = len(s) % 5
     # Pad the last quantum with zero bits if necessary
     if leftover:
-        s = s + bytes(5 - leftover)  # Don't use += !
+        s = s + b'\0' * (5 - leftover)  # Don't use += !
     encoded = bytearray()
     from_bytes = int.from_bytes
     b32tab2 = _b32tab2