posix: always seek to EOF when opening a file in append mode
Python 3 already does this, so skip it there.
Consider the program:
#include <stdio.h>
int main() {
FILE *f = fopen("narf", "w");
fprintf(f, "narf\n");
fclose(f);
f = fopen("narf", "a");
printf("%ld\n", ftell(f));
fprintf(f, "troz\n");
printf("%ld\n", ftell(f));
return 0;
}
on macOS, FreeBSD, and Linux with glibc, this program prints
5
10
but on musl libc (Alpine Linux and probably others) this prints
0
10
By my reading of
https://pubs.opengroup.org/onlinepubs/009695399/functions/fopen.html
this is technically correct, specifically:
> Opening a file with append mode (a as the first character in the
> mode argument) shall cause all subsequent writes to the file to be
> forced to the then current end-of-file, regardless of intervening
> calls to fseek().
in other words, the file position doesn't really matter in append-mode
files, and we can't depend on it being at all meaningful unless we
perform a seek() before tell() after open(..., 'a'). Experimentally
after a .write() we can do a .tell() and it'll always be reasonable,
but I'm unclear from reading the specification if that's a smart thing
to rely on. This matches what we do on Windows and what Python 3 does
for free, so let's just be consistent. Thanks to Yuya for the idea.
$ hg init a
$ hg clone a b
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd a
with no paths:
$ hg paths
$ hg paths unknown
not found!
[1]
$ hg paths -Tjson
[
]
with paths:
$ echo '[paths]' >> .hg/hgrc
$ echo 'dupe = ../b#tip' >> .hg/hgrc
$ echo 'expand = $SOMETHING/bar' >> .hg/hgrc
$ hg in dupe
comparing with $TESTTMP/b
no changes found
[1]
$ cd ..
$ hg -R a in dupe
comparing with $TESTTMP/b
no changes found
[1]
$ cd a
$ hg paths
dupe = $TESTTMP/b#tip
expand = $TESTTMP/a/$SOMETHING/bar
$ SOMETHING=foo hg paths
dupe = $TESTTMP/b#tip
expand = $TESTTMP/a/foo/bar
#if msys
$ SOMETHING=//foo hg paths
dupe = $TESTTMP/b#tip
expand = /foo/bar
#else
$ SOMETHING=/foo hg paths
dupe = $TESTTMP/b#tip
expand = /foo/bar
#endif
$ hg paths -q
dupe
expand
$ hg paths dupe
$TESTTMP/b#tip
$ hg paths -q dupe
$ hg paths unknown
not found!
[1]
$ hg paths -q unknown
[1]
formatter output with paths:
$ echo 'dupe:pushurl = https://example.com/dupe' >> .hg/hgrc
$ hg paths -Tjson | sed 's|\\\\|\\|g'
[
{
"name": "dupe",
"pushurl": "https://example.com/dupe",
"url": "$TESTTMP/b#tip"
},
{
"name": "expand",
"url": "$TESTTMP/a/$SOMETHING/bar"
}
]
$ hg paths -Tjson dupe | sed 's|\\\\|\\|g'
[
{
"name": "dupe",
"pushurl": "https://example.com/dupe",
"url": "$TESTTMP/b#tip"
}
]
$ hg paths -Tjson -q unknown
[
]
[1]
log template:
(behaves as a {name: path-string} dict by default)
$ hg log -rnull -T '{peerurls}\n'
dupe=$TESTTMP/b#tip expand=$TESTTMP/a/$SOMETHING/bar
$ hg log -rnull -T '{join(peerurls, "\n")}\n'
dupe=$TESTTMP/b#tip
expand=$TESTTMP/a/$SOMETHING/bar
$ hg log -rnull -T '{peerurls % "{name}: {url}\n"}'
dupe: $TESTTMP/b#tip
expand: $TESTTMP/a/$SOMETHING/bar
$ hg log -rnull -T '{get(peerurls, "dupe")}\n'
$TESTTMP/b#tip
(sub options can be populated by map/dot operation)
$ hg log -rnull \
> -T '{get(peerurls, "dupe") % "url: {url}\npushurl: {pushurl}\n"}'
url: $TESTTMP/b#tip
pushurl: https://example.com/dupe
$ hg log -rnull -T '{peerurls.dupe.pushurl}\n'
https://example.com/dupe
(in JSON, it's a dict of urls)
$ hg log -rnull -T '{peerurls|json}\n' | sed 's|\\\\|/|g'
{"dupe": "$TESTTMP/b#tip", "expand": "$TESTTMP/a/$SOMETHING/bar"}
password should be masked in plain output, but not in machine-readable/template
output:
$ echo 'insecure = http://foo:insecure@example.com/' >> .hg/hgrc
$ hg paths insecure
http://foo:***@example.com/
$ hg paths -Tjson insecure
[
{
"name": "insecure",
"url": "http://foo:insecure@example.com/"
}
]
$ hg log -rnull -T '{get(peerurls, "insecure")}\n'
http://foo:insecure@example.com/
zeroconf wraps ui.configitems(), which shouldn't crash at least:
$ hg paths --config extensions.zeroconf=
dupe = $TESTTMP/b#tip
dupe:pushurl = https://example.com/dupe
expand = $TESTTMP/a/$SOMETHING/bar
insecure = http://foo:***@example.com/
$ cd ..
sub-options for an undeclared path are ignored
$ hg init suboptions
$ cd suboptions
$ cat > .hg/hgrc << EOF
> [paths]
> path0 = https://example.com/path0
> path1:pushurl = https://example.com/path1
> EOF
$ hg paths
path0 = https://example.com/path0
unknown sub-options aren't displayed
$ cat > .hg/hgrc << EOF
> [paths]
> path0 = https://example.com/path0
> path0:foo = https://example.com/path1
> EOF
$ hg paths
path0 = https://example.com/path0
:pushurl must be a URL
$ cat > .hg/hgrc << EOF
> [paths]
> default = /path/to/nothing
> default:pushurl = /not/a/url
> EOF
$ hg paths
(paths.default:pushurl not a URL; ignoring)
default = /path/to/nothing
#fragment is not allowed in :pushurl
$ cat > .hg/hgrc << EOF
> [paths]
> default = https://example.com/repo
> invalid = https://example.com/repo
> invalid:pushurl = https://example.com/repo#branch
> EOF
$ hg paths
("#fragment" in paths.invalid:pushurl not supported; ignoring)
default = https://example.com/repo
invalid = https://example.com/repo
invalid:pushurl = https://example.com/repo
$ cd ..
'file:' disables [paths] entries for clone destination
$ cat >> $HGRCPATH <<EOF
> [paths]
> gpath1 = http://hg.example.com
> EOF
$ hg clone a gpath1
abort: cannot create new http repository
[255]
$ hg clone a file:gpath1
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd gpath1
$ hg -q id
000000000000
$ cd ..