tests/test-hgwebdirsym.t

commit: use `dirstate.change_files` to scope the associated `addremove`

This was significantly more complicated than I expected, because multiple
extensions get in the way.

I introduced a context that lazily open the transaction and associated context
to work around these complication. See the inline documentation for details.

Introducing the wrapping transaction remove the need for dirstate-guard (one of
the ultimate goal of all this), and slightly affect the result of a `hg
rollback` after a `hg commit --addremove`. That last part is deemed fine. It
aligns the behavior with what happens after a failed `hg commit --addremove` and
nobody should be using `hg rollback` anyway.

The small output change in the test come from the different transaction timing
and fact the transaction now backup the dirstate before the addremove, which
might mean "no file to backup" when the repository starts from an empty state.

#require serve symlink

Tests whether or not hgwebdir properly handles various symlink topologies.

hide outer repo
  $ hg init

  $ hg init a
  $ echo a > a/a
  $ hg --cwd a ci -Ama -d'1 0'
  adding a
  $ mkdir webdir
  $ cd webdir
  $ hg init b
  $ echo b > b/b
  $ hg --cwd b ci -Amb -d'2 0'
  adding b
  $ hg init c
  $ echo c > c/c
  $ hg --cwd c ci -Amc -d'3 0'
  adding c
  $ ln -s ../a al
  $ ln -s ../webdir circle
  $ root=`pwd`
  $ cd ..
  $ cat > collections.conf <<EOF
  > [collections]
  > $root=$root
  > EOF
  $ hg serve -p $HGPORT -d --pid-file=hg.pid --webdir-conf collections.conf \
  >     -A access-collections.log -E error-collections.log
  $ cat hg.pid >> $DAEMON_PIDS

should succeed

  $ get-with-headers.py localhost:$HGPORT '?style=raw'
  200 Script output follows
  
  
  /al/
  /b/
  /c/
  
  $ get-with-headers.py localhost:$HGPORT 'al/file/tip/a?style=raw'
  200 Script output follows
  
  a
  $ get-with-headers.py localhost:$HGPORT 'b/file/tip/b?style=raw'
  200 Script output follows
  
  b
  $ get-with-headers.py localhost:$HGPORT 'c/file/tip/c?style=raw'
  200 Script output follows
  
  c

should fail

  $ get-with-headers.py localhost:$HGPORT 'circle/al/file/tip/a?style=raw'
  404 Not Found
  
  
  error: repository circle/al/file/tip/a not found
  [1]
  $ get-with-headers.py localhost:$HGPORT 'circle/b/file/tip/a?style=raw'
  404 Not Found
  
  
  error: repository circle/b/file/tip/a not found
  [1]
  $ get-with-headers.py localhost:$HGPORT 'circle/c/file/tip/a?style=raw'
  404 Not Found
  
  
  error: repository circle/c/file/tip/a not found
  [1]

collections errors

  $ cat error-collections.log