view tests/test-revert-interactive.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

Revert interactive tests
1 add and commit file f
2 add commit file folder1/g
3 add and commit file folder2/h
4 add and commit file folder1/i
5 commit change to file f
6 commit changes to files folder1/g folder2/h
7 commit changes to files folder1/g folder2/h
8 revert interactive to commit id 2 (line 3 above), check that folder1/i is removed and
9 make workdir match 7
10 run the same test than 8 from within folder1 and check same expectations

  $ cat <<EOF >> $HGRCPATH
  > [ui]
  > interactive = true
  > [extensions]
  > record =
  > purge = 
  > EOF


  $ mkdir -p a/folder1 a/folder2
  $ cd a
  $ hg init
  >>> open('f', 'wb').write(b"1\n2\n3\n4\n5\n") and None
  $ hg add f ; hg commit -m "adding f"
  $ cat f > folder1/g ; hg add folder1/g ; hg commit -m "adding folder1/g"
  $ cat f > folder2/h ; hg add folder2/h ; hg commit -m "adding folder2/h"
  $ cat f > folder1/i ; hg add folder1/i ; hg commit -m "adding folder1/i"
  >>> open('f', 'wb').write(b"a\n1\n2\n3\n4\n5\nb\n") and None
  $ hg commit -m "modifying f"
  >>> open('folder1/g', 'wb').write(b"c\n1\n2\n3\n4\n5\nd\n") and None
  $ hg commit -m "modifying folder1/g"
  >>> open('folder2/h', 'wb').write(b"e\n1\n2\n3\n4\n5\nf\n") and None
  $ hg commit -m "modifying folder2/h"
  $ hg tip
  changeset:   6:59dd6e4ab63a
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modifying folder2/h
  
  $ hg revert -i -r 2 --all -- << EOF
  > y
  > y
  > y
  > y
  > y
  > ?
  > y
  > n
  > n
  > EOF
  remove added file folder1/i (Yn)? y
  removing folder1/i
  diff --git a/f b/f
  2 hunks, 2 lines changed
  examine changes to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,6 +1,5 @@
  -a
   1
   2
   3
   4
   5
  apply change 1/6 to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -2,6 +1,5 @@
   1
   2
   3
   4
   5
  -b
  apply change 2/6 to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  diff --git a/folder1/g b/folder1/g
  2 hunks, 2 lines changed
  examine changes to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,6 +1,5 @@
  -c
   1
   2
   3
   4
   5
  apply change 3/6 to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] ?
  
  y - yes, apply this change
  n - no, skip this change
  e - edit this change manually
  s - skip remaining changes to this file
  f - apply remaining changes to this file
  d - done, skip remaining changes and files
  a - apply all changes to all remaining files
  q - quit, applying no changes
  ? - ? (display help)
  apply change 3/6 to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -2,6 +1,5 @@
   1
   2
   3
   4
   5
  -d
  apply change 4/6 to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] n
  
  diff --git a/folder2/h b/folder2/h
  2 hunks, 2 lines changed
  examine changes to 'folder2/h'?
  (enter ? for help) [Ynesfdaq?] n
  
  reverting f
  reverting folder1/g
  $ cat f
  1
  2
  3
  4
  5
  $ cat folder1/g
  1
  2
  3
  4
  5
  d
  $ cat folder2/h
  e
  1
  2
  3
  4
  5
  f

Test that --interactive lift the need for --all

  $ echo q | hg revert -i -r 2
  diff --git a/folder1/g b/folder1/g
  1 hunks, 1 lines changed
  examine changes to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] q
  
  abort: user quit
  [250]
  $ ls folder1/
  g

Test that a noop revert doesn't do an unnecessary backup
  $ (echo n) | hg revert -i -r 2 folder1/g
  diff --git a/folder1/g b/folder1/g
  1 hunks, 1 lines changed
  @@ -3,4 +3,3 @@
   3
   4
   5
  -d
  apply this change to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] n
  
  $ ls folder1/
  g

Test --no-backup
  $ (echo y) | hg revert -i -C -r 2 folder1/g
  diff --git a/folder1/g b/folder1/g
  1 hunks, 1 lines changed
  @@ -3,4 +3,3 @@
   3
   4
   5
  -d
  apply this change to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] y
  
  $ ls folder1/
  g
  >>> open('folder1/g', 'wb').write(b"1\n2\n3\n4\n5\nd\n") and None


  $ hg update -C 6
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg revert -i -r 2 --all -- << EOF
  > n
  > y
  > y
  > y
  > y
  > y
  > n
  > n
  > EOF
  remove added file folder1/i (Yn)? n
  diff --git a/f b/f
  2 hunks, 2 lines changed
  examine changes to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,6 +1,5 @@
  -a
   1
   2
   3
   4
   5
  apply change 1/6 to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -2,6 +1,5 @@
   1
   2
   3
   4
   5
  -b
  apply change 2/6 to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  diff --git a/folder1/g b/folder1/g
  2 hunks, 2 lines changed
  examine changes to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,6 +1,5 @@
  -c
   1
   2
   3
   4
   5
  apply change 3/6 to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -2,6 +1,5 @@
   1
   2
   3
   4
   5
  -d
  apply change 4/6 to 'folder1/g'?
  (enter ? for help) [Ynesfdaq?] n
  
  diff --git a/folder2/h b/folder2/h
  2 hunks, 2 lines changed
  examine changes to 'folder2/h'?
  (enter ? for help) [Ynesfdaq?] n
  
  reverting f
  reverting folder1/g
  $ cat f
  1
  2
  3
  4
  5
  $ cat folder1/g
  1
  2
  3
  4
  5
  d
  $ cat folder2/h
  e
  1
  2
  3
  4
  5
  f
  $ hg st
  M f
  M folder1/g
  $ hg revert --interactive f << EOF
  > ?
  > y
  > n
  > n
  > EOF
  diff --git a/f b/f
  2 hunks, 2 lines changed
  @@ -1,6 +1,5 @@
  -a
   1
   2
   3
   4
   5
  discard change 1/2 to 'f'?
  (enter ? for help) [Ynesfdaq?] ?
  
  y - yes, discard this change
  n - no, skip this change
  e - edit this change manually
  s - skip remaining changes to this file
  f - discard remaining changes to this file
  d - done, skip remaining changes and files
  a - discard all changes to all remaining files
  q - quit, discarding no changes
  ? - ? (display help)
  discard change 1/2 to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -2,6 +1,5 @@
   1
   2
   3
   4
   5
  -b
  discard change 2/2 to 'f'?
  (enter ? for help) [Ynesfdaq?] n
  
  $ hg st
  M f
  M folder1/g
  ? f.orig
  $ cat f
  a
  1
  2
  3
  4
  5
  $ cat f.orig
  1
  2
  3
  4
  5
  $ rm f.orig

Patterns

  $ hg revert -i 'glob:f*' << EOF
  > y
  > n
  > EOF
  diff --git a/f b/f
  1 hunks, 1 lines changed
  examine changes to 'f'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -4,4 +4,3 @@
   3
   4
   5
  -b
  discard this change to 'f'?
  (enter ? for help) [Ynesfdaq?] n
  

  $ hg update -C .
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

Check editing files newly added by a revert

1) Create a dummy editor changing 1 to 42
  $ cat > $TESTTMP/editor.sh << '__EOF__'
  > cat "$1"  | sed "s/1/42/g"  > tt
  > mv tt  "$1"
  > __EOF__

2) Add k
  $ printf "1\n" > k
  $ hg add k
  $ hg commit -m "add k"

3) Use interactive revert with editing (replacing +1 with +42):
  $ printf "0\n2\n" > k
  $ HGEDITOR="\"sh\" \"${TESTTMP}/editor.sh\"" hg revert -i  <<EOF
  > y
  > e
  > EOF
  diff --git a/k b/k
  1 hunks, 2 lines changed
  examine changes to 'k'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,1 +1,2 @@
  -1
  +0
  +2
  discard this change to 'k'?
  (enter ? for help) [Ynesfdaq?] e
  
  reverting k
  $ cat k
  42

  $ hg update -C .
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg purge
  $ touch newfile
  $ hg add newfile
  $ hg status
  A newfile
  $ hg revert -i <<EOF
  > n
  > EOF
  forget added file newfile (Yn)? n
  $ hg status
  A newfile
  $ hg revert -i <<EOF
  > y
  > EOF
  forget added file newfile (Yn)? y
  forgetting newfile
  $ hg status
  ? newfile

When a line without EOL is selected during "revert -i" (issue5651)

  $ hg init $TESTTMP/revert-i-eol
  $ cd $TESTTMP/revert-i-eol
  $ echo 0 > a
  $ hg ci -qAm 0
  $ printf 1 >> a
  $ hg ci -qAm 1
  $ cat a
  0
  1 (no-eol)

  $ hg revert -ir'.^' <<EOF
  > y
  > y
  > EOF
  diff --git a/a b/a
  1 hunks, 1 lines changed
  examine changes to 'a'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,2 +1,1 @@
   0
  -1
  \ No newline at end of file
  apply this change to 'a'?
  (enter ? for help) [Ynesfdaq?] y
  
  reverting a
  $ cat a
  0

When specified pattern does not exist, we should exit early (issue5789).

  $ hg files
  a
  $ hg rev b
  b: no such file in rev b40d1912accf
  $ hg rev -i b
  b: no such file in rev b40d1912accf

  $ cd ..

Prompt before undeleting file(issue6008)
  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -qAm a
  $ hg rm a
  $ hg revert -i<<EOF
  > y
  > EOF
  add back removed file a (Yn)? y
  undeleting a
  $ ls -A
  .hg
  a
  $ hg rm a
  $ hg revert -i<<EOF
  > n
  > EOF
  add back removed file a (Yn)? n
  $ ls -A
  .hg
  $ hg revert -a
  undeleting a
  $ cd ..

Test "keep" mode

  $ cat <<EOF >> $HGRCPATH
  > [experimental]
  > revert.interactive.select-to-keep = true
  > EOF

  $ cd repo
  $ printf "x\na\ny\n" > a
  $ hg diff
  diff -r cb9a9f314b8b a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,3 @@
  +x
   a
  +y
  $ cat > $TESTTMP/editor.sh << '__EOF__'
  > echo "+new line" >> "$1"
  > __EOF__

  $ HGEDITOR="\"sh\" \"${TESTTMP}/editor.sh\"" hg revert -i  <<EOF
  > y
  > n
  > e
  > EOF
  diff --git a/a b/a
  2 hunks, 2 lines changed
  examine changes to 'a'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,1 +1,2 @@
  +x
   a
  keep change 1/2 to 'a'?
  (enter ? for help) [Ynesfdaq?] n
  
  @@ -1,1 +2,2 @@
   a
  +y
  keep change 2/2 to 'a'?
  (enter ? for help) [Ynesfdaq?] e
  
  reverting a
  $ cat a
  a
  y
  new line