view tests/test-convert-svn-encoding.t @ 46607:e9901d01d135

revlog: add a mechanism to verify expected file position before appending

If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.

The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)

When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.

For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.

This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.

Differential Revision: https://phab.mercurial-scm.org/D9952

#require svn svn-bindings

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

  $ svnadmin create svn-repo
  $ svnadmin load -q svn-repo < "$TESTDIR/svn/encoding.svndump"

Convert while testing all possible outputs

  $ hg --debug convert svn-repo A-hg --config progress.debug=1
  initializing destination A-hg repository
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  run hg sink pre-conversion action
  scanning source...
  found trunk at 'trunk'
  found tags at 'tags'
  found branches at 'branches'
  found branch branch\xc3\xa9 at 5 (esc)
  found branch branch\xc3\xa9e at 6 (esc)
  scanning: 1/4 revisions (25.00%)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  fetching revision log for "/trunk" from 4 to 0
  parsing revision 4 (2 changes)
  parsing revision 3 (4 changes)
  parsing revision 2 (3 changes)
  parsing revision 1 (3 changes)
  no copyfrom path, don't know what to do.
  '/branches' is not under '/trunk', ignoring
  '/tags' is not under '/trunk', ignoring
  scanning: 2/4 revisions (50.00%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  fetching revision log for "/branches/branch\xc3\xa9" from 5 to 0 (esc)
  parsing revision 5 (1 changes)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  found parent of branch /branches/branch\xc3\xa9 at 4: /trunk (esc)
  scanning: 3/4 revisions (75.00%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  fetching revision log for "/branches/branch\xc3\xa9e" from 6 to 0 (esc)
  parsing revision 6 (1 changes)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  found parent of branch /branches/branch\xc3\xa9e at 5: /branches/branch\xc3\xa9 (esc)
  scanning: 4/4 revisions (100.00%)
  scanning: 5/4 revisions (125.00%)
  scanning: 6/4 revisions (150.00%)
  sorting...
  converting...
  5 init projA
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@1
  converting: 0/6 revisions (0.00%)
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  4 hello
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@2
  converting: 1/6 revisions (16.67%)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xa0 0/3 paths (0.00%) (esc)
  scanning paths: /trunk/\xc3\xa0/e\xcc\x81 1/3 paths (33.33%) (esc)
  scanning paths: /trunk/\xc3\xa9 2/3 paths (66.67%) (esc)
  committing files:
  \xc3\xa0/e\xcc\x81 (esc)
  getting files: \xc3\xa0/e\xcc\x81 1/2 files (50.00%) (esc)
  \xc3\xa9 (esc)
  getting files: \xc3\xa9 2/2 files (100.00%) (esc)
  committing manifest
  committing changelog
  updating the branch cache
  3 copy files
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@3
  converting: 2/6 revisions (33.33%)
  scanning paths: /trunk/\xc3\xa0 0/4 paths (0.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xa8 1/4 paths (25.00%) (esc)
  copied to \xc3\xa8 from \xc3\xa9@2 (esc)
  scanning paths: /trunk/\xc3\xa9 2/4 paths (50.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xb9 3/4 paths (75.00%) (esc)
  mark /trunk/\xc3\xb9 came from \xc3\xa0:2 (esc)
  getting files: \xc3\xa0/e\xcc\x81 1/4 files (25.00%) (esc)
  getting files: \xc3\xa9 2/4 files (50.00%) (esc)
  committing files:
  \xc3\xa8 (esc)
  getting files: \xc3\xa8 3/4 files (75.00%) (esc)
   \xc3\xa8: copy \xc3\xa9:6b67ccefd5ce6de77e7ead4f5292843a0255329f (esc)
  \xc3\xb9/e\xcc\x81 (esc)
  getting files: \xc3\xb9/e\xcc\x81 4/4 files (100.00%) (esc)
   \xc3\xb9/e\xcc\x81: copy \xc3\xa0/e\xcc\x81:a9092a3d84a37b9993b5c73576f6de29b7ea50f6 (esc)
  committing manifest
  committing changelog
  updating the branch cache
  2 remove files
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/trunk@4
  converting: 3/6 revisions (50.00%)
  scanning paths: /trunk/\xc3\xa8 0/2 paths (0.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  scanning paths: /trunk/\xc3\xb9 1/2 paths (50.00%) (esc)
  gone from -1
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/trunk (glob)
  getting files: \xc3\xa8 1/2 files (50.00%) (esc)
  getting files: \xc3\xb9/e\xcc\x81 2/2 files (100.00%) (esc)
  committing files:
  committing manifest
  committing changelog
  updating the branch cache
  1 branch to branch?
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/branches/branch?@5
  converting: 4/6 revisions (66.67%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9 (glob)
  scanning paths: /branches/branch\xc3\xa9 0/1 paths (0.00%) (esc)
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  0 branch to branch?e
  source: svn:afeb9c47-92ff-4c0c-9f72-e1f6eb8ac9af/branches/branch?e@6
  converting: 5/6 revisions (83.33%)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  scanning paths: /branches/branch\xc3\xa9e 0/1 paths (0.00%) (esc)
  reusing manifest from p1 (no file change)
  committing changelog
  updating the branch cache
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  reparent to file:/*/$TESTTMP/svn-repo (glob)
  reparent to file:/*/$TESTTMP/svn-repo/branches/branch%C3%A9e (glob)
  updating tags
  committing files:
  .hgtags
  committing manifest
  committing changelog
  updating the branch cache
  run hg sink post-conversion action
  $ cd A-hg
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

Check tags are in UTF-8

  $ cat .hgtags
  e94e4422020e715add80525e8f0f46c9968689f1 branch\xc3\xa9e (esc)
  f7e66f98380ed1e53a797c5c7a7a2616a7ab377d branch\xc3\xa9 (esc)

  $ cd ..

Subversion sources don't support non-ASCII characters in HTTP(S) URLs.

  $ XFF=$($PYTHON -c 'from mercurial.utils.procutil import stdout; stdout.write(b"\xff")')
  $ hg convert --source-type=svn http://localhost:$HGPORT/$XFF test
  initializing destination test repository
  Subversion sources don't support non-ASCII characters in HTTP(S) URLs. Please percent-encode them.
  http://localhost:$HGPORT/\xff does not look like a Subversion repository (esc)
  abort: http://localhost:$HGPORT/\xff: missing or unsupported repository (esc)
  [255]

In Subversion, paths are Unicode (encoded as UTF-8). Therefore paths that can't
be converted between UTF-8 and the locale encoding (which is always ASCII in
tests) don't work.

  $ cp -R svn-repo $XFF
  $ hg convert $XFF test
  initializing destination test repository
  Subversion requires that paths can be converted to Unicode using the current locale encoding (ascii)
  \xff does not look like a CVS checkout (glob) (esc)
  $TESTTMP/\xff does not look like a Git repository (esc)
  \xff does not look like a Subversion repository (glob) (esc)
  \xff is not a local Mercurial repository (glob) (esc)
  \xff does not look like a darcs repository (glob) (esc)
  \xff does not look like a monotone repository (glob) (esc)
  \xff does not look like a GNU Arch repository (glob) (esc)
  \xff does not look like a Bazaar repository (glob) (esc)
  cannot find required "p4" tool
  abort: \xff: missing or unsupported repository (glob) (esc)
  [255]
  $ hg convert file://$TESTTMP/$XFF test
  initializing destination test repository
  Subversion requires that file URLs can be converted to Unicode using the current locale encoding (ascii)
  file:/*/$TESTTMP/\xff does not look like a CVS checkout (glob) (esc)
  $TESTTMP/file:$TESTTMP/\xff does not look like a Git repository (esc)
  file:/*/$TESTTMP/\xff does not look like a Subversion repository (glob) (esc)
  file:/*/$TESTTMP/\xff is not a local Mercurial repository (glob) (esc)
  file:/*/$TESTTMP/\xff does not look like a darcs repository (glob) (esc)
  file:/*/$TESTTMP/\xff does not look like a monotone repository (glob) (esc)
  file:/*/$TESTTMP/\xff does not look like a GNU Arch repository (glob) (esc)
  file:/*/$TESTTMP/\xff does not look like a Bazaar repository (glob) (esc)
  file:/*/$TESTTMP/\xff does not look like a P4 repository (glob) (esc)
  abort: file:/*/$TESTTMP/\xff: missing or unsupported repository (glob) (esc)
  [255]

Subversion decodes percent-encoded bytes on the converted, UTF-8-encoded
string. Therefore, if the percent-encoded bytes aren't valid UTF-8, Subversion
would choke on them when converting them to the locale encoding.

  $ hg convert file://$TESTTMP/%FF test
  initializing destination test repository
  Subversion does not support non-UTF-8 percent-encoded bytes in file URLs
  file:/*/$TESTTMP/%FF does not look like a CVS checkout (glob)
  $TESTTMP/file:$TESTTMP/%FF does not look like a Git repository
  file:/*/$TESTTMP/%FF does not look like a Subversion repository (glob)
  file:/*/$TESTTMP/%FF is not a local Mercurial repository (glob)
  file:/*/$TESTTMP/%FF does not look like a darcs repository (glob)
  file:/*/$TESTTMP/%FF does not look like a monotone repository (glob)
  file:/*/$TESTTMP/%FF does not look like a GNU Arch repository (glob)
  file:/*/$TESTTMP/%FF does not look like a Bazaar repository (glob)
  file:/*/$TESTTMP/%FF does not look like a P4 repository (glob)
  abort: file:/*/$TESTTMP/%FF: missing or unsupported repository (glob)
  [255]