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.
Test changesets filtering during exchanges (some tests are still in
test-obsolete.t)
$ cat >> $HGRCPATH << EOF
> [experimental]
> evolution=createmarkers
> EOF
Push does not corrupt remote
----------------------------
Create a DAG where a changeset reuses a revision from a file first used in an
extinct changeset.
$ hg init local
$ cd local
$ echo 'base' > base
$ hg commit -Am base
adding base
$ echo 'A' > A
$ hg commit -Am A
adding A
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg revert -ar 1
adding A
$ hg commit -Am "A'"
created new head
$ hg log -G --template='{desc} {node}'
@ A' f89bcc95eba5174b1ccc3e33a82e84c96e8338ee
|
| o A 9d73aac1b2ed7d53835eaeec212ed41ea47da53a
|/
o base d20a80d4def38df63a4b330b7fb688f3d4cae1e3
$ hg debugobsolete 9d73aac1b2ed7d53835eaeec212ed41ea47da53a f89bcc95eba5174b1ccc3e33a82e84c96e8338ee
Push it. The bundle should not refer to the extinct changeset.
$ hg init ../other
$ hg push ../other
pushing to ../other
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 2 files
$ hg -R ../other verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 2 changesets, 2 total revisions
Adding a changeset going extinct locally
------------------------------------------
Pull a changeset that will immediatly goes extinct (because you already have a
marker to obsolete him)
(test resolution of issue3788)
$ hg phase --draft --force f89bcc95eba5
$ hg phase -R ../other --draft --force f89bcc95eba5
$ hg commit --amend -m "A''"
$ hg --hidden --config extensions.mq= strip --no-backup f89bcc95eba5
$ hg pull ../other
pulling from ../other
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
check that bundle is not affected
$ hg bundle --hidden --rev f89bcc95eba5 --base "f89bcc95eba5^" ../f89bcc95eba5.hg
1 changesets found
$ hg --hidden --config extensions.mq= strip --no-backup f89bcc95eba5
$ hg unbundle ../f89bcc95eba5.hg
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 1 files (+1 heads)
(run 'hg heads' to see heads)
$ cd ..
pull does not fetch excessive changesets when common node is hidden (issue4982)
-------------------------------------------------------------------------------
initial repo with server and client matching
$ hg init pull-hidden-common
$ cd pull-hidden-common
$ touch foo
$ hg -q commit -A -m initial
$ echo 1 > foo
$ hg commit -m 1
$ echo 2a > foo
$ hg commit -m 2a
$ cd ..
$ hg clone --pull pull-hidden-common pull-hidden-common-client
requesting all changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
server obsoletes the old head
$ cd pull-hidden-common
$ hg -q up -r 1
$ echo 2b > foo
$ hg -q commit -m 2b
$ hg debugobsolete 6a29ed9c68defff1a139e5c6fa9696fb1a75783d bec0734cd68e84477ba7fc1d13e6cff53ab70129
$ cd ..
client only pulls down 1 changeset
$ cd pull-hidden-common-client
$ hg pull --debug
pulling from $TESTTMP/pull-hidden-common (glob)
query 1; heads
searching for changes
taking quick initial sample
query 2; still undecided: 2, sample size is: 2
2 total queries
1 changesets found
list of changesets:
bec0734cd68e84477ba7fc1d13e6cff53ab70129
listing keys for "phase"
listing keys for "bookmarks"
bundle2-output-bundle: "HG20", 3 parts total
bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
bundle2-output-part: "listkeys" (params: 1 mandatory) empty payload
bundle2-output-part: "listkeys" (params: 1 mandatory) empty payload
bundle2-input-bundle: with-transaction
bundle2-input-part: "changegroup" (params: 1 mandatory 1 advisory) supported
adding changesets
add changeset bec0734cd68e
adding manifests
adding file changes
adding foo revisions
added 1 changesets with 1 changes to 1 files (+1 heads)
bundle2-input-part: total payload size 474
bundle2-input-part: "listkeys" (params: 1 mandatory) supported
bundle2-input-part: "listkeys" (params: 1 mandatory) supported
bundle2-input-bundle: 2 parts total
checking for updated bookmarks
listing keys for "phases"
updating the branch cache
(run 'hg heads' to see heads, 'hg merge' to merge)