[3.9] bpo-29566: binhex.binhex now consitently writes MacOS 9 line endings. (GH-23059) (GH-23071)

[[bpo-29566]()]() notes that binhex.binhex uses inconsistent line endings (both Unix and MacOS9 line endings are used). This PR changes this to use the MacOS9 line endings everywhere.
(cherry picked from commit 2165cea)


Co-authored-by: Ronald Oussoren <[email protected]>

Automerge-Triggered-By: GH:ronaldoussoren

Author: miss-islington

Lib/binhex.py

@@ -117,12 +117,12 @@ def _flush(self, force):
         first = 0
         while first <= len(self.hqxdata) - self.linelen:
             last = first + self.linelen
-            self.ofp.write(self.hqxdata[first:last] + b'\n')
+            self.ofp.write(self.hqxdata[first:last] + b'\r')
             self.linelen = LINELEN
             first = last
         self.hqxdata = self.hqxdata[first:]
         if force:
-            self.ofp.write(self.hqxdata + b':\n')
+            self.ofp.write(self.hqxdata + b':\r')
 
     def close(self):
         if self.data:

Lib/test/test_binhex.py

@@ -48,6 +48,18 @@ def test_binhex_error_on_long_filename(self):
 
         self.assertRaises(binhex.Error, binhex.binhex, self.fname3, self.fname2)
 
+    def test_binhex_line_endings(self):
+        # bpo-29566: Ensure the line endings are those for macOS 9
+        with open(self.fname1, 'wb') as f:
+            f.write(self.DATA)
+
+        binhex.binhex(self.fname1, self.fname2)
+
+        with open(self.fname2, 'rb') as fp:
+            contents = fp.read()
+
+        self.assertNotIn(b'\n', contents)
+
 def test_main():
     support.run_unittest(BinHexTestCase)
 

Misc/NEWS.d/next/Library/2020-10-31-13-28-36.bpo-29566.6aDbty.rst

@@ -0,0 +1 @@
+``binhex.binhex()`` consisently writes macOS 9 line endings.