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.
#require symlink
== tests added in 0.7 ==
$ hg init test-symlinks-0.7; cd test-symlinks-0.7;
$ touch foo; ln -s foo bar; ln -s nonexistent baz
import with add and addremove -- symlink walking should _not_ screwup.
$ hg add
adding bar
adding baz
adding foo
$ hg forget bar baz foo
$ hg addremove
adding bar
adding baz
adding foo
commit -- the symlink should _not_ appear added to dir state
$ hg commit -m 'initial'
$ touch bomb
again, symlink should _not_ show up on dir state
$ hg addremove
adding bomb
Assert screamed here before, should go by without consequence
$ hg commit -m 'is there a bug?'
$ cd ..
== fifo & ignore ==
$ hg init test; cd test;
$ mkdir dir
$ touch a.c dir/a.o dir/b.o
test what happens if we want to trick hg
$ hg commit -A -m 0
adding a.c
adding dir/a.o
adding dir/b.o
$ echo "relglob:*.o" > .hgignore
$ rm a.c
$ rm dir/a.o
$ rm dir/b.o
$ mkdir dir/a.o
$ ln -s nonexistent dir/b.o
$ mkfifo a.c
it should show a.c, dir/a.o and dir/b.o deleted
$ hg status
M dir/b.o
! a.c
! dir/a.o
? .hgignore
$ hg status a.c
a.c: unsupported file type (type is fifo)
! a.c
$ cd ..
== symlinks from outside the tree ==
test absolute path through symlink outside repo
$ p=`pwd`
$ hg init x
$ ln -s x y
$ cd x
$ touch f
$ hg add f
$ hg status "$p"/y/f
A f
try symlink outside repo to file inside
$ ln -s x/f ../z
this should fail
$ hg status ../z && { echo hg mistakenly exited with status 0; exit 1; } || :
abort: ../z not under root '$TESTTMP/x'
$ cd ..
== cloning symlinks ==
$ hg init clone; cd clone;
try cloning symlink in a subdir
1. commit a symlink
$ mkdir -p a/b/c
$ cd a/b/c
$ ln -s /path/to/symlink/source demo
$ cd ../../..
$ hg stat
? a/b/c/demo
$ hg commit -A -m 'add symlink in a/b/c subdir'
adding a/b/c/demo
2. clone it
$ cd ..
$ hg clone clone clonedest
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
== symlink and git diffs ==
git symlink diff
$ cd clonedest
$ hg diff --git -r null:tip
diff --git a/a/b/c/demo b/a/b/c/demo
new file mode 120000
--- /dev/null
+++ b/a/b/c/demo
@@ -0,0 +1,1 @@
+/path/to/symlink/source
\ No newline at end of file
$ hg export --git tip > ../sl.diff
import git symlink diff
$ hg rm a/b/c/demo
$ hg commit -m'remove link'
$ hg import ../sl.diff
applying ../sl.diff
$ hg diff --git -r 1:tip
diff --git a/a/b/c/demo b/a/b/c/demo
new file mode 120000
--- /dev/null
+++ b/a/b/c/demo
@@ -0,0 +1,1 @@
+/path/to/symlink/source
\ No newline at end of file
== symlinks and addremove ==
directory moved and symlinked
$ mkdir foo
$ touch foo/a
$ hg ci -Ama
adding foo/a
$ mv foo bar
$ ln -s bar foo
$ hg status
! foo/a
? bar/a
? foo
now addremove should remove old files
$ hg addremove
adding bar/a
adding foo
removing foo/a
commit and update back
$ hg ci -mb
$ hg up '.^'
1 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg up tip
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cd ..
== root of repository is symlinked ==
$ hg init root
$ ln -s root link
$ cd root
$ echo foo > foo
$ hg status
? foo
$ hg status ../link
? foo
$ hg add foo
$ hg cp foo "$TESTTMP/link/bar"
foo has not been committed yet, so no copy data will be stored for bar.
$ cd ..
$ hg init b
$ cd b
$ ln -s nothing dangling
$ hg commit -m 'commit symlink without adding' dangling
abort: dangling: file not tracked!
[255]
$ hg add dangling
$ hg commit -m 'add symlink'
$ hg tip -v
changeset: 0:cabd88b706fc
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: dangling
description:
add symlink
$ hg manifest --debug
2564acbe54bbbedfbf608479340b359f04597f80 644 @ dangling
$ readlink.py dangling
dangling -> nothing
$ rm dangling
$ ln -s void dangling
$ hg commit -m 'change symlink'
$ readlink.py dangling
dangling -> void
modifying link
$ rm dangling
$ ln -s empty dangling
$ readlink.py dangling
dangling -> empty
reverting to rev 0:
$ hg revert -r 0 -a
reverting dangling
$ readlink.py dangling
dangling -> nothing
backups:
$ readlink.py *.orig
dangling.orig -> empty
$ rm *.orig
$ hg up -C
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
copies
$ hg cp -v dangling dangling2
copying dangling to dangling2
$ hg st -Cmard
A dangling2
dangling
$ readlink.py dangling dangling2
dangling -> void
dangling2 -> void
Issue995: hg copy -A incorrectly handles symbolic links
$ hg up -C
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ mkdir dir
$ ln -s dir dirlink
$ hg ci -qAm 'add dirlink'
$ mkdir newdir
$ mv dir newdir/dir
$ mv dirlink newdir/dirlink
$ hg mv -A dirlink newdir/dirlink
$ cd ..