tests/test-pushvars.t

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.

Setup

  $ PYTHONPATH=$TESTDIR/..:$PYTHONPATH
  $ export PYTHONPATH

  $ cat > $TESTTMP/pretxnchangegroup.sh << EOF
  > #!/bin/sh
  > env | egrep "^HG_USERVAR_(DEBUG|BYPASS_REVIEW)" | sort
  > exit 0
  > EOF
  $ cat >> $HGRCPATH << EOF
  > [hooks]
  > pretxnchangegroup = sh $TESTTMP/pretxnchangegroup.sh
  > EOF

  $ hg init repo
  $ hg clone -q repo child
  $ cd child

Test pushing vars to repo with pushvars.server not set

  $ echo b > a
  $ hg commit -Aqm a
  $ hg push --pushvars "DEBUG=1" --pushvars "BYPASS_REVIEW=true"
  pushing to $TESTTMP/repo
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files

Setting pushvars.sever = true and then pushing.

  $ echo [push] >> $HGRCPATH
  $ echo "pushvars.server = true" >> $HGRCPATH
  $ echo b >> a
  $ hg commit -Aqm a
  $ hg push --pushvars "DEBUG=1" --pushvars "BYPASS_REVIEW=true"
  pushing to $TESTTMP/repo
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  HG_USERVAR_BYPASS_REVIEW=true
  HG_USERVAR_DEBUG=1

Test pushing var with empty right-hand side

  $ echo b >> a
  $ hg commit -Aqm a
  $ hg push --pushvars "DEBUG="
  pushing to $TESTTMP/repo
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  HG_USERVAR_DEBUG=

Test pushing bad vars

  $ echo b >> a
  $ hg commit -Aqm b
  $ hg push --pushvars "DEBUG"
  pushing to $TESTTMP/repo
  searching for changes
  abort: unable to parse variable 'DEBUG', should follow 'KEY=VALUE' or 'KEY=' format
  [255]