Re: git archive --format zip utf-8 issues

Hi,

I found a way to make unzip respect the UTF-8 flag in ZIP files: 
Apparently (from looking at the source) an extended field needs to be 
present in order for it to even look at general purpose flag 11.  I sent 
a patch to add an extended timestamp field that fits the bill.

Here are new numbers on ZIP international filename compatibility:

		7-Zip	PeaZip	builtin	unzip	unzip	unzip	7z
		Windows	Windows	Windows	Linux	mingw	Windows	Linux
git	Linux	1	1	1	7	1	1	1
git 1	Linux	37	37	1	7	1	1	37
git 2	Linux	37	37	1	37	1	1	37
git 3	Linux	37	37	1	37	15	15	37
git	mingw	1	1	1	7	1	1	1
git 1	mingw	37	37	1	7	1	1	37
git 2	mingw	37	37	1	37	1	1	37
git 3	mingw	37	37	1	37	15	15	37
7-Zip	Windows	37	37	14	24	15	15	24
PeaZip	Windows	37	37	14	24	15	15	24
zip	Linux	37	37	1	37	15	15	37
zip	Windows	14	14	0	37	15	15	1
builtin	Windows	14	14	14	1	14	14	1

The test corpus still consists of 37 files based on the pangrams on the 
following web page:

	http://www.columbia.edu/~fdc/utf8/index.html#quickbrownfox

The files can be created using the attached script.  It also provides a 
check command to count the files with correct names, and the results of 
that for different ZIP extractors are give in the table.  The built-in 
ZIP functionality on Windows was only able to pack 14 of the 37 files, 
which explains the low score across the board for this packer.

"git 1" is the patch "archive-zip: support UTF-8 paths" added, which 
let's archive-zip make use of the UTF-8 flag.  "git 2" is "git 1" plus 
the patch "archive-zip: declare creator to be Unix for UTF-8 paths". 
Both have been posted before.  "git 3" is "git 1" plus the new patch 
"archive-zip: write extended timestamp".

Let's drop patch 2 (Unix as creator) and keep patches 1 (UTF-8 flag) and 
3 (mtime field) to make archive-zip record non-ASCII filenames in a 
portable way.  It's not perfect, but I don't know how to do any better 
given that Windows' built-in ZIP functionality expects filenames in the 
local code page and with an international audience for projects 
distributing ZIP files.

René