revset: add experimental support for extdata
This is minimal and non-controversial implementation of extdata() revset.
Originally extdata sources were exposed to the symbol namespace, but I've
changed it to a plain function for simplicity.
$ hg init repo
$ cd repo
$ for n in 0 1 2 3; do
> echo $n > $n
> hg ci -qAm $n
> done
test revset support
$ cat <<'EOF' >> .hg/hgrc
> [extdata]
> filedata = file:extdata.txt
> shelldata = shell:cat extdata.txt | grep 2
> EOF
$ cat <<'EOF' > extdata.txt
> 2
> 3
> EOF
$ hg log -qr "extdata(filedata)"
2:f6ed99a58333
3:9de260b1e88e
$ hg log -qr "extdata(shelldata)"
2:f6ed99a58333
test weight of extdata() revset
$ hg debugrevspec -p optimized "extdata(filedata) & 3"
* optimized:
(andsmally
(func
(symbol 'extdata')
(symbol 'filedata'))
(symbol '3'))
3
test bad extdata() revset source
$ hg log -qr "extdata()"
hg: parse error: extdata takes at least 1 string argument
[255]
$ hg log -qr "extdata(unknown)"
abort: unknown extdata source 'unknown'
[255]
we don't fix up relative file URLs, but we do run shell commands in repo root
$ mkdir sub
$ cd sub
$ hg log -qr "extdata(filedata)"
abort: error: No such file or directory
[255]
$ hg log -qr "extdata(shelldata)"
2:f6ed99a58333
$ cd ..