--timestamping with --output-document delete file data on second run
$ wget2 -V
GNU Wget2 1.99.1 - multithreaded metalink/file/website downloader
this works:
$ wget2 -N https://en.wikipedia.org/static/images/icons/wikipedia.png
[0] Downloading 'https://en.wikipedia.org/static/images/icons/wikipedia.png' ...
Saving 'wikipedia.png'
HTTP response 200 [https://en.wikipedia.org/static/images/icons/wikipedia.png]
$ ls -l wikipedia.png
-rw-r--r-- 1 pavel pavel 13444 kvě 6 14:25 wikipedia.png
$ wget2 -N https://en.wikipedia.org/static/images/icons/wikipedia.png
[0] Downloading 'https://en.wikipedia.org/static/images/icons/wikipedia.png' ...
HTTP response 304 [https://en.wikipedia.org/static/images/icons/wikipedia.png]
$ ls -l wikipedia.png
-rw-r--r-- 1 pavel pavel 13444 kvě 6 14:25 wikipedia.png
this delete all data in file
$ wget2 -N https://en.wikipedia.org/static/images/icons/wikipedia.png -O wikipedia2.png
[0] Downloading 'https://en.wikipedia.org/static/images/icons/wikipedia.png' ...
Saving 'wikipedia2.png'
HTTP response 200 [https://en.wikipedia.org/static/images/icons/wikipedia.png]
$ ls -l wikipedia2.png
-rw-r--r-- 1 pavel pavel 13444 kvě 6 14:25 wikipedia2.png
$ wget2 -N https://en.wikipedia.org/static/images/icons/wikipedia.png -O wikipedia2.png
[0] Downloading 'https://en.wikipedia.org/static/images/icons/wikipedia.png' ...
HTTP response 304 [https://en.wikipedia.org/static/images/icons/wikipedia.png]
$ ls -l wikipedia2.png
-rw-r--r-- 1 pavel pavel 0 kvě 13 16:31 wikipedia2.png
Edited by Pavel Cibulka