tests/test-remotefilelog-corrupt-cache.t

rhg: Port Python’s `ui.configlist` as `Config::get_list`

This new method is not used yet outside of its own unit tests,
so this changeset should make no observable change.

The Rust parser implementation attempts to exactly replicate the behavior of
the Python one, even in edge cases where that behavior is… surprising.
New unit tests capture some of these edge cases.

This started as a line-by-line port. The main changes are:

* Pass around a parser mode enum instead of parser functions
* Inline the whole parser into one function
* Use `[u8]::get` which returns an `Option`,
  instead of indexing  after explicitly checking the length.

Differential Revision: https://phab.mercurial-scm.org/D11389

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
  $ echo x > x
  $ echo y > y
  $ echo z > z
  $ hg commit -qAm xy

  $ cd ..

  $ hgcloneshallow ssh://user@dummy/master shallow -q
  3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
  $ cd shallow

Verify corrupt cache handling repairs by default

  $ hg up -q null
  $ chmod u+w $CACHEDIR/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
  $ echo x > $CACHEDIR/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
  $ hg up tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)

Verify corrupt cache error message

  $ hg up -q null
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > validatecache=off
  > EOF
  $ chmod u+w $CACHEDIR/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
  $ echo x > $CACHEDIR/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
  $ hg up tip 2>&1 | egrep "^[^ ].*unexpected remotefilelog"
  abort: unexpected remotefilelog header: illegal format (no-py3 !)
  hgext.remotefilelog.shallowutil.BadRemotefilelogHeader: unexpected remotefilelog header: illegal format (py3 !)

Verify detection and remediation when remotefilelog.validatecachelog is set

  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > validatecachelog=$PWD/.hg/remotefilelog_cache.log
  > validatecache=strict
  > EOF
  $ chmod u+w $CACHEDIR/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
  $ echo x > $CACHEDIR/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
  $ hg up tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
  $ cat .hg/remotefilelog_cache.log
  corrupt $TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0 during contains

Verify handling of corrupt server cache

  $ rm -f ../master/.hg/remotefilelogcache/y/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
  $ touch ../master/.hg/remotefilelogcache/y/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
  $ clearcache
  $ hg prefetch -r .
  3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
  $ test -s ../master/.hg/remotefilelogcache/y/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
  $ hg debugremotefilelog $CACHEDIR/master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
  size: 2 bytes
  path: $TESTTMP/hgcache/master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca 
  key: 076f5e2225b3 
  
          node =>           p1            p2      linknode     copyfrom
  076f5e2225b3 => 000000000000  000000000000  f3d0bb0d1e48