archival: don't set gzip filename header when there's no filename
This mainly affects hgweb, which can generate tar.gz archives without
filenames. Without this change, the header would be set to ".gz",
which can confuse Safari into extracting the file and renaming it to
"gz" when "Open 'safe' files after downloading" is enabled.
file(1) before:
hg-crew-5e51254ad4d4.tar.gz: gzip compressed data, was ".gz", last modified: Thu Dec 2 11:46:20 2010, max compression
after:
hg-crew-5e51254ad4d4.tar.gz: gzip compressed data, last modified: Thu Dec 2 11:46:20 2010, max compression
$ mkdir a
$ cd a
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "a" -u a
$ cd ..
$ mkdir b
$ cd b
$ hg init
$ echo 321 > b
$ hg add b
$ hg commit -m "b" -u b
$ hg pull ../a
pulling from ../a
searching for changes
abort: repository is unrelated
[255]
$ hg pull -f ../a
pulling from ../a
searching for changes
warning: repository is unrelated
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg heads
changeset: 1:9a79c33a9db3
tag: tip
parent: -1:000000000000
user: a
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
changeset: 0:01f8062b2de5
user: b
date: Thu Jan 01 00:00:00 1970 +0000
summary: b