Fixes #10639: reindent.py should not convert newlines
reindent.py now will use the newline detected in the original file and will report an error if mixed newlines are encountered.
diff --git a/Misc/NEWS b/Misc/NEWS
index 662eedc..d91a993 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -310,6 +310,12 @@
   "make install" creates symlinks in --prefix bin for the "-32" files in the
   framework bin directory like the installer does.
 
+Tools/Demos
+-----------
+
+- Issue #10639: reindent.py no longer converts newlines and will raise
+  an error if attempting to convert a file with mixed newlines.
+
 Tests
 -----