view tests/test-url-download.t @ 42377:0546ead39a7e stable

manifest: avoid corruption by dropping removed files with pure (issue5801)

Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`.  But no effort was made to
ignore them when compacting the dictionary into text form.  This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible.  As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry.   This typically resulted in
a ValueError complaining about unsorted manifest entries.

Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot.  A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.

In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes.  However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.

[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511

#require serve

  $ hg init server
  $ hg serve -R server -p $HGPORT -d --pid-file=hg1.pid -E ../error.log
  $ cat hg1.pid >> $DAEMON_PIDS

Check basic fetching

  $ hg debugdownload "http://localhost:$HGPORT/?cmd=lookup&key=tip"
  1 0000000000000000000000000000000000000000
  $ hg debugdownload  -o null.txt "http://localhost:$HGPORT/?cmd=lookup&key=null"
  $ cat null.txt
  1 0000000000000000000000000000000000000000

Check the request is made from the usual Mercurial logic
(rev details, give different content if the request has a Mercurial user agent)

  $ get-with-headers.py --headeronly "localhost:$HGPORT" "rev/tip" content-type
  200 Script output follows
  content-type: text/html; charset=ascii
  $ hg debugdownload "http://localhost:$HGPORT/rev/tip"
  
  # HG changeset patch
  # User 
  # Date 0 0
  # Node ID 0000000000000000000000000000000000000000
  
  
  
  

Check other kind of compatible url

  $ hg debugdownload ./null.txt
  1 0000000000000000000000000000000000000000

Test largefile URL
------------------

  $ cat << EOF >> $HGRCPATH
  > [extensions]
  > largefiles=
  > EOF

  $ killdaemons.py
  $ rm -f error.log hg1.pid
  $ hg serve -R server -p $HGPORT -d --pid-file=hg1.pid -E error.log
  $ cat hg1.pid >> $DAEMON_PIDS

  $ hg -R server debuglfput null.txt
  a57b57b39ee4dc3da1e03526596007f480ecdbe8

  $ hg --traceback debugdownload "largefile://a57b57b39ee4dc3da1e03526596007f480ecdbe8" --config paths.default=http://localhost:$HGPORT/
  1 0000000000000000000000000000000000000000

from within a repository

  $ hg clone http://localhost:$HGPORT/ client
  no changes found
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd client
  $ hg path
  default = http://localhost:$HGPORT/
  $ hg debugdownload "largefile://a57b57b39ee4dc3da1e03526596007f480ecdbe8"
  1 0000000000000000000000000000000000000000
  $ cd ..