shar (with compression) does not handle filename with sapces

Dear maintainer,

shar does not handle filenames with spaces in them if using compression
(ie gzip or xz).  It creates the archive without comment but then when
trying to extract the archive it fails with an error message.

This is the error message:
x - created lock directory _sh03236.
x - extracting Filename with spaces.txt gzipped
uudecode fatal error:
fserr 2 (No such file or directory) performing 'freopen' on Filename
with _sh03236/gzi
restore of Filename with spaces.txt failed
Filename with spaces.txt: MD5 check failed
x - removed lock directory _sh03236.


I have confirmed that the bug is present in the current upstream version.

The program works correctly with filenames containing spaces if you do
not specify compression.

Thank you