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.
The simple store doesn't escape paths robustly and can't store paths
with periods, etc. So much of this test fails with it.
#require no-reposimplestore
$ hg init
audit of .hg
$ hg add .hg/00changelog.i
abort: path contains illegal component: .hg/00changelog.i
[255]
#if symlink
Symlinks
$ mkdir a
$ echo a > a/a
$ hg ci -Ama
adding a/a
$ ln -s a b
$ echo b > a/b
$ hg add b/b
abort: path 'b/b' traverses symbolic link 'b'
[255]
$ hg add b
should still fail - maybe
$ hg add b/b
abort: path 'b/b' traverses symbolic link 'b'
[255]
$ hg commit -m 'add symlink b'
Test symlink traversing when accessing history:
-----------------------------------------------
(build a changeset where the path exists as a directory)
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mkdir b
$ echo c > b/a
$ hg add b/a
$ hg ci -m 'add directory b'
created new head
Test that hg cat does not do anything wrong the working copy has 'b' as directory
$ hg cat b/a
c
$ hg cat -r "desc(directory)" b/a
c
$ hg cat -r "desc(symlink)" b/a
b/a: no such file in rev bc151a1f53bd
[1]
Test that hg cat does not do anything wrong the working copy has 'b' as a symlink (issue4749)
$ hg up 'desc(symlink)'
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg cat b/a
b/a: no such file in rev bc151a1f53bd
[1]
$ hg cat -r "desc(directory)" b/a
c
$ hg cat -r "desc(symlink)" b/a
b/a: no such file in rev bc151a1f53bd
[1]
#endif
unbundle tampered bundle
$ hg init target
$ cd target
$ hg unbundle "$TESTDIR/bundles/tampered.hg"
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 6 files (+4 heads)
new changesets b7da9bf6b037:fc1393d727bc (5 drafts)
(run 'hg heads' to see heads, 'hg merge' to merge)
attack .hg/test
$ hg manifest -r0
.hg/test
$ hg update -Cr0
abort: path contains illegal component: .hg/test
[255]
attack foo/.hg/test
$ hg manifest -r1
foo/.hg/test
$ hg update -Cr1
abort: path 'foo/.hg/test' is inside nested repo 'foo'
[255]
attack back/test where back symlinks to ..
$ hg manifest -r2
back
back/test
#if symlink
$ hg update -Cr2
abort: path 'back/test' traverses symbolic link 'back'
[255]
#else
('back' will be a file and cause some other system specific error)
$ hg update -Cr2
abort: $TESTTMP/target/back/test: $ENOTDIR$
[255]
#endif
attack ../test
$ hg manifest -r3
../test
$ mkdir ../test
$ echo data > ../test/file
$ hg update -Cr3
abort: path contains illegal component: ../test
[255]
$ cat ../test/file
data
attack /tmp/test
$ hg manifest -r4
/tmp/test
$ hg update -Cr4
abort: path contains illegal component: /tmp/test
[255]
$ cd ..
Test symlink traversal on merge:
--------------------------------
#if symlink
set up symlink hell
$ mkdir merge-symlink-out
$ hg init merge-symlink
$ cd merge-symlink
$ touch base
$ hg commit -qAm base
$ ln -s ../merge-symlink-out a
$ hg commit -qAm 'symlink a -> ../merge-symlink-out'
$ hg up -q 0
$ mkdir a
$ touch a/poisoned
$ hg commit -qAm 'file a/poisoned'
$ hg log -G -T '{rev}: {desc}\n'
@ 2: file a/poisoned
|
| o 1: symlink a -> ../merge-symlink-out
|/
o 0: base
try trivial merge
$ hg up -qC 1
$ hg merge 2
abort: path 'a/poisoned' traverses symbolic link 'a'
[255]
try rebase onto other revision: cache of audited paths should be discarded,
and the rebase should fail (issue5628)
$ hg up -qC 2
$ hg rebase -s 2 -d 1 --config extensions.rebase=
rebasing 2:e73c21d6b244 "file a/poisoned" (tip)
abort: path 'a/poisoned' traverses symbolic link 'a'
[255]
$ ls ../merge-symlink-out
$ cd ..
Test symlink traversal on update:
---------------------------------
$ mkdir update-symlink-out
$ hg init update-symlink
$ cd update-symlink
$ ln -s ../update-symlink-out a
$ hg commit -qAm 'symlink a -> ../update-symlink-out'
$ hg rm a
$ mkdir a && touch a/b
$ hg ci -qAm 'file a/b' a/b
$ hg up -qC 0
$ hg rm a
$ mkdir a && touch a/c
$ hg ci -qAm 'rm a, file a/c'
$ hg log -G -T '{rev}: {desc}\n'
@ 2: rm a, file a/c
|
| o 1: file a/b
|/
o 0: symlink a -> ../update-symlink-out
try linear update where symlink already exists:
$ hg up -qC 0
$ hg up 1
abort: path 'a/b' traverses symbolic link 'a'
[255]
try linear update including symlinked directory and its content: paths are
audited first by calculateupdates(), where no symlink is created so both
'a' and 'a/b' are taken as good paths. still applyupdates() should fail.
$ hg up -qC null
$ hg up 1
abort: path 'a/b' traverses symbolic link 'a'
[255]
$ ls ../update-symlink-out
try branch update replacing directory with symlink, and its content: the
path 'a' is audited as a directory first, which should be audited again as
a symlink.
$ rm -f a
$ hg up -qC 2
$ hg up 1
abort: path 'a/b' traverses symbolic link 'a'
[255]
$ ls ../update-symlink-out
$ cd ..
#endif