Preserve CRLF if file already ends that way
diff --git a/pre_commit_hooks/end_of_file_fixer.py b/pre_commit_hooks/end_of_file_fixer.py
index 9b94ab3..37ebbb5 100644
--- a/pre_commit_hooks/end_of_file_fixer.py
+++ b/pre_commit_hooks/end_of_file_fixer.py
@@ -35,14 +35,14 @@
last_character = file_obj.read(1)
# Our current position is at the end of the file just before any amount of
- # newlines. If we read two characters and get two newlines back we know
- # there are extraneous newlines at the ned of the file. Then backtrack and
- # trim the end off.
- if len(file_obj.read(2)) == 2:
- file_obj.seek(-2, os.SEEK_CUR)
- file_obj.truncate()
- file_obj.write(b'\n')
- return 1
+ # newlines. If we find extraneous newlines, then backtrack and trim them.
+ position = file_obj.tell()
+ remaining = file_obj.read()
+ for sequence in [b'\n', b'\r\n']:
+ if remaining.startswith(sequence) and len(remaining) > len(sequence):
+ file_obj.seek(position + len(sequence))
+ file_obj.truncate()
+ return 1
return 0
