repoview: discard filtered changelog if index isn't shared with unfiltered
Before this patch, revisions rollbacked at failure of previous
transaction might be visible at subsequent operations unintentionally,
if repoview object is reused even after failure of transaction:
e.g. command server and HTTP server are typical cases.
'repoview' uses the tuple of values below of unfiltered changelog as
"the key" to examine validity of filtered changelog cache.
- length
- tip node
- filtered revisions (as hashed value)
- '_delayed' field
'repoview' compares between "the key" of unfiltered changelog at
previous caching and now, and reuses filtered changelog cache if no
change is detected.
But this comparison indicates only that there is no change between
unfiltered 'repo.changelog' at last caching and now, but not that
filtered changelog cache is valid for current unfiltered one.
'repoview' uses "shallow copy" of unfiltered changelog to create
filtered changelog cache. In this case, 'index' buffer of unfiltered
changelog is also referred by filtered changelog.
At failure of transaction, unfiltered changelog itself is invalidated
(= un-referred) on the 'repo' side (see
0a7610758c42 also). But
'index' of it still contains revisions to be rollbacked at this
failure, and is referred by filtered changelog.
Therefore, even if there is no change between unfiltered
'repo.changelog' at last caching and now, steps below makes rollbacked
revisions visible via filtered changelog unintentionally.
1. instantiate unfiltered changelog as 'repo.changelog'
(call it CL1)
2. make filtered (= shallow copy of) CL1
(call it FCL1)
3. cache FCL1 with "the key" of CL1
4. revisions are appended to 'index', which is shared by CL1 and FCL1
5. invalidate 'repo.changelog' (= CL1) at failure of transaction
6. instantiate 'repo.changelog' again at next operation
(call it CL2)
CL2 doesn't have revisions added at (4), because it is
instantiated from '00changelog.i', which isn't changed while
failed transaction.
7. compare between "the key" of CL1 and CL2
8. FCL1 cached at (3) is reused, because comparison at (7) doesn't
detect change between CL1 at (1) and CL2
9. revisions rollbacked at (5) are visible via FCL1 unintentionally,
because FCL1 still refers 'index' changed at (4)
The root cause of this issue is that there is no examination about
validity of filtered changelog cache against current unfiltered one.
This patch discards filtered changelog cache, if its 'index' object
isn't shared with unfiltered one.
BTW, at the time of this patch, redundant truncation of
'00changelog.i' at failure of transaction (see
0a7610758c42 for
detail) often prevents "hg serve" from making already rollbacked
revisions visible, because updating timestamps of '00changelog.i' by
truncation makes "hg serve" discard old repoview object with invalid
filtered changelog cache.
This is reason why this issue is overlooked before this patch, even
though test-bundle2-exchange.t has tests in similar situation: failure
of "hg push" via HTTP by pretxnclose hook on server side doesn't
prevent subsequent commands from looking up outgoing revisions
correctly.
But timestamp on the filesystem doesn't have enough resolution for
recent computation power, and it can't be assumed that this avoidance
always works as expected.
Therefore, without this patch, this issue might appear occasionally.
$ cat <<EOF >> $HGRCPATH
> [extensions]
> purge =
> EOF
init
$ hg init t
$ cd t
setup
$ echo r1 > r1
$ hg ci -qAmr1 -d'0 0'
$ mkdir directory
$ echo r2 > directory/r2
$ hg ci -qAmr2 -d'1 0'
$ echo 'ignored' > .hgignore
$ hg ci -qAmr3 -d'2 0'
delete an empty directory
$ mkdir empty_dir
$ hg purge -p -v
empty_dir
$ hg purge -v
removing directory empty_dir
$ ls
directory
r1
delete an untracked directory
$ mkdir untracked_dir
$ touch untracked_dir/untracked_file1
$ touch untracked_dir/untracked_file2
$ hg purge -p
untracked_dir/untracked_file1
untracked_dir/untracked_file2
$ hg purge -v
removing file untracked_dir/untracked_file1
removing file untracked_dir/untracked_file2
removing directory untracked_dir
$ ls
directory
r1
delete an untracked file
$ touch untracked_file
$ touch untracked_file_readonly
$ python <<EOF
> import os, stat
> f= 'untracked_file_readonly'
> os.chmod(f, stat.S_IMODE(os.stat(f).st_mode) & ~stat.S_IWRITE)
> EOF
$ hg purge -p
untracked_file
untracked_file_readonly
$ hg purge -v
removing file untracked_file
removing file untracked_file_readonly
$ ls
directory
r1
delete an untracked file in a tracked directory
$ touch directory/untracked_file
$ hg purge -p
directory/untracked_file
$ hg purge -v
removing file directory/untracked_file
$ ls
directory
r1
delete nested directories
$ mkdir -p untracked_directory/nested_directory
$ hg purge -p
untracked_directory/nested_directory
$ hg purge -v
removing directory untracked_directory/nested_directory
removing directory untracked_directory
$ ls
directory
r1
delete nested directories from a subdir
$ mkdir -p untracked_directory/nested_directory
$ cd directory
$ hg purge -p
untracked_directory/nested_directory
$ hg purge -v
removing directory untracked_directory/nested_directory
removing directory untracked_directory
$ cd ..
$ ls
directory
r1
delete only part of the tree
$ mkdir -p untracked_directory/nested_directory
$ touch directory/untracked_file
$ cd directory
$ hg purge -p ../untracked_directory
untracked_directory/nested_directory
$ hg purge -v ../untracked_directory
removing directory untracked_directory/nested_directory
removing directory untracked_directory
$ cd ..
$ ls
directory
r1
$ ls directory/untracked_file
directory/untracked_file
$ rm directory/untracked_file
skip ignored files if --all not specified
$ touch ignored
$ hg purge -p
$ hg purge -v
$ ls
directory
ignored
r1
$ hg purge -p --all
ignored
$ hg purge -v --all
removing file ignored
$ ls
directory
r1
abort with missing files until we support name mangling filesystems
$ touch untracked_file
$ rm r1
hide error messages to avoid changing the output when the text changes
$ hg purge -p 2> /dev/null
untracked_file
$ hg st
! r1
? untracked_file
$ hg purge -p
untracked_file
$ hg purge -v 2> /dev/null
removing file untracked_file
$ hg st
! r1
$ hg purge -v
$ hg revert --all --quiet
$ hg st -a
tracked file in ignored directory (issue621)
$ echo directory >> .hgignore
$ hg ci -m 'ignore directory'
$ touch untracked_file
$ hg purge -p
untracked_file
$ hg purge -v
removing file untracked_file
skip excluded files
$ touch excluded_file
$ hg purge -p -X excluded_file
$ hg purge -v -X excluded_file
$ ls
directory
excluded_file
r1
$ rm excluded_file
skip files in excluded dirs
$ mkdir excluded_dir
$ touch excluded_dir/file
$ hg purge -p -X excluded_dir
$ hg purge -v -X excluded_dir
$ ls
directory
excluded_dir
r1
$ ls excluded_dir
file
$ rm -R excluded_dir
skip excluded empty dirs
$ mkdir excluded_dir
$ hg purge -p -X excluded_dir
$ hg purge -v -X excluded_dir
$ ls
directory
excluded_dir
r1
$ rmdir excluded_dir
skip patterns
$ mkdir .svn
$ touch .svn/foo
$ mkdir directory/.svn
$ touch directory/.svn/foo
$ hg purge -p -X .svn -X '*/.svn'
$ hg purge -p -X re:.*.svn
$ rm -R .svn directory r1
only remove files
$ mkdir -p empty_dir dir
$ touch untracked_file dir/untracked_file
$ hg purge -p --files
dir/untracked_file
untracked_file
$ hg purge -v --files
removing file dir/untracked_file
removing file untracked_file
$ ls
dir
empty_dir
$ ls dir
only remove dirs
$ mkdir -p empty_dir dir
$ touch untracked_file dir/untracked_file
$ hg purge -p --dirs
empty_dir
$ hg purge -v --dirs
removing directory empty_dir
$ ls
dir
untracked_file
$ ls dir
untracked_file
remove both files and dirs
$ mkdir -p empty_dir dir
$ touch untracked_file dir/untracked_file
$ hg purge -p --files --dirs
dir/untracked_file
untracked_file
empty_dir
$ hg purge -v --files --dirs
removing file dir/untracked_file
removing file untracked_file
removing directory empty_dir
removing directory dir
$ ls
$ cd ..