tests/test-rebase-cache.t

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 >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > mq=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog  = log -G --template "{rev}: '{desc}' {branches}\n"
  > theads = heads --template "{rev}: '{desc}' {branches}\n"
  > EOF

  $ hg init a
  $ cd a

  $ echo a > a
  $ hg ci -Am A
  adding a

  $ hg branch branch1
  marked working directory as branch branch1
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -m 'branch1'

  $ echo b > b
  $ hg ci -Am B
  adding b

  $ hg up -q 0

  $ hg branch branch2
  marked working directory as branch branch2
  $ hg ci -m 'branch2'

  $ echo c > C
  $ hg ci -Am C
  adding C

  $ hg up -q 2

  $ hg branch -f branch2
  marked working directory as branch branch2
  $ echo d > d
  $ hg ci -Am D
  adding d
  created new head

  $ echo e > e
  $ hg ci -Am E
  adding e

  $ hg update default
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved

  $ hg branch branch3
  marked working directory as branch branch3
  $ hg ci -m 'branch3'

  $ echo f > f
  $ hg ci -Am F
  adding f

  $ cd ..


Rebase part of branch2 (5-6) onto branch3 (8):

  $ hg clone -q -u . a a1
  $ cd a1

  $ hg tglog
  @  8: 'F' branch3
  |
  o  7: 'branch3' branch3
  |
  | o  6: 'E' branch2
  | |
  | o  5: 'D' branch2
  | |
  | | o  4: 'C' branch2
  | | |
  +---o  3: 'branch2' branch2
  | |
  | o  2: 'B' branch1
  | |
  | o  1: 'branch1' branch1
  |/
  o  0: 'A'
  
  $ hg branches
  branch3                        8:4666b71e8e32
  branch2                        6:5097051d331d
  branch1                        2:0a03079c47fd (inactive)
  default                        0:1994f17a630e (inactive)

  $ hg theads
  8: 'F' branch3
  6: 'E' branch2
  4: 'C' branch2
  2: 'B' branch1
  0: 'A' 

  $ hg rebase -s 5 -d 8
  rebasing 5:635859577d0b "D"
  rebasing 6:5097051d331d "E"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/635859577d0b-89160bff-backup.hg (glob)

  $ hg branches
  branch3                        8:466cdfb14b62
  branch2                        4:e4fdb121d036
  branch1                        2:0a03079c47fd
  default                        0:1994f17a630e (inactive)

  $ hg theads
  8: 'E' branch3
  4: 'C' branch2
  2: 'B' branch1
  0: 'A' 

  $ hg tglog
  o  8: 'E' branch3
  |
  o  7: 'D' branch3
  |
  @  6: 'F' branch3
  |
  o  5: 'branch3' branch3
  |
  | o  4: 'C' branch2
  | |
  | o  3: 'branch2' branch2
  |/
  | o  2: 'B' branch1
  | |
  | o  1: 'branch1' branch1
  |/
  o  0: 'A'
  
  $ cd ..


Rebase head of branch3 (8) onto branch2 (6):

  $ hg clone -q -u . a a2
  $ cd a2

  $ hg tglog
  @  8: 'F' branch3
  |
  o  7: 'branch3' branch3
  |
  | o  6: 'E' branch2
  | |
  | o  5: 'D' branch2
  | |
  | | o  4: 'C' branch2
  | | |
  +---o  3: 'branch2' branch2
  | |
  | o  2: 'B' branch1
  | |
  | o  1: 'branch1' branch1
  |/
  o  0: 'A'
  
  $ hg rebase -s 8 -d 6
  rebasing 8:4666b71e8e32 "F" (tip)
  saved backup bundle to $TESTTMP/a2/.hg/strip-backup/4666b71e8e32-fc1c4e96-backup.hg (glob)

  $ hg branches
  branch2                        8:6b4bdc1b5ac0
  branch3                        7:653b9feb4616
  branch1                        2:0a03079c47fd (inactive)
  default                        0:1994f17a630e (inactive)

  $ hg theads
  8: 'F' branch2
  7: 'branch3' branch3
  4: 'C' branch2
  2: 'B' branch1
  0: 'A' 

  $ hg tglog
  @  8: 'F' branch2
  |
  | o  7: 'branch3' branch3
  | |
  o |  6: 'E' branch2
  | |
  o |  5: 'D' branch2
  | |
  | | o  4: 'C' branch2
  | | |
  | | o  3: 'branch2' branch2
  | |/
  o |  2: 'B' branch1
  | |
  o |  1: 'branch1' branch1
  |/
  o  0: 'A'
  
  $ hg verify -q

  $ cd ..


Rebase entire branch3 (7-8) onto branch2 (6):

  $ hg clone -q -u . a a3
  $ cd a3

  $ hg tglog
  @  8: 'F' branch3
  |
  o  7: 'branch3' branch3
  |
  | o  6: 'E' branch2
  | |
  | o  5: 'D' branch2
  | |
  | | o  4: 'C' branch2
  | | |
  +---o  3: 'branch2' branch2
  | |
  | o  2: 'B' branch1
  | |
  | o  1: 'branch1' branch1
  |/
  o  0: 'A'
  
  $ hg rebase -s 7 -d 6
  rebasing 7:653b9feb4616 "branch3"
  note: rebase of 7:653b9feb4616 created no changes to commit
  rebasing 8:4666b71e8e32 "F" (tip)
  saved backup bundle to $TESTTMP/a3/.hg/strip-backup/653b9feb4616-3c88de16-backup.hg (glob)

  $ hg branches
  branch2                        7:6b4bdc1b5ac0
  branch1                        2:0a03079c47fd (inactive)
  default                        0:1994f17a630e (inactive)

  $ hg theads
  7: 'F' branch2
  4: 'C' branch2
  2: 'B' branch1
  0: 'A' 

  $ hg tglog
  @  7: 'F' branch2
  |
  o  6: 'E' branch2
  |
  o  5: 'D' branch2
  |
  | o  4: 'C' branch2
  | |
  | o  3: 'branch2' branch2
  | |
  o |  2: 'B' branch1
  | |
  o |  1: 'branch1' branch1
  |/
  o  0: 'A'
  
  $ hg verify -q

Stripping multiple branches in one go bypasses the fast-case code to
update the branch cache.

  $ hg strip 2
  0 files updated, 0 files merged, 4 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/a3/.hg/strip-backup/0a03079c47fd-11b7c407-backup.hg (glob)

  $ hg tglog
  o  3: 'C' branch2
  |
  o  2: 'branch2' branch2
  |
  | @  1: 'branch1' branch1
  |/
  o  0: 'A'
  

  $ hg branches
  branch2                        3:e4fdb121d036
  branch1                        1:63379ac49655
  default                        0:1994f17a630e (inactive)

  $ hg theads
  3: 'C' branch2
  1: 'branch1' branch1
  0: 'A' 

Fast path branchcache code should not be invoked if branches stripped is not
the same as branches remaining.

  $ hg init b
  $ cd b

  $ hg branch branch1
  marked working directory as branch branch1
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -m 'branch1'

  $ hg branch branch2
  marked working directory as branch branch2
  $ hg ci -m 'branch2'

  $ hg branch -f branch1
  marked working directory as branch branch1

  $ echo a > A
  $ hg ci -Am A
  adding A
  created new head

  $ hg tglog
  @  2: 'A' branch1
  |
  o  1: 'branch2' branch2
  |
  o  0: 'branch1' branch1
  

  $ hg theads
  2: 'A' branch1
  1: 'branch2' branch2

  $ hg strip 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/a3/b/.hg/strip-backup/a5b4b27ed7b4-a3b6984e-backup.hg (glob)

  $ hg theads
  1: 'branch2' branch2
  0: 'branch1' branch1


Make sure requesting to strip a revision already stripped does not confuse things.
Try both orders.

  $ cd ..

  $ hg init c
  $ cd c

  $ echo a > a
  $ hg ci -Am A
  adding a
  $ echo b > b
  $ hg ci -Am B
  adding b
  $ echo c > c
  $ hg ci -Am C
  adding c
  $ echo d > d
  $ hg ci -Am D
  adding d
  $ echo e > e
  $ hg ci -Am E
  adding e

  $ hg tglog
  @  4: 'E'
  |
  o  3: 'D'
  |
  o  2: 'C'
  |
  o  1: 'B'
  |
  o  0: 'A'
  

  $ hg strip 3 4
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/a3/c/.hg/strip-backup/67a385d4e6f2-b9243789-backup.hg (glob)

  $ hg theads
  2: 'C' 

  $ hg strip 2 1
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/a3/c/.hg/strip-backup/6c81ed0049f8-a687065f-backup.hg (glob)

  $ hg theads
  0: 'A' 

Make sure rebase does not break for phase/filter related reason
----------------------------------------------------------------
(issue3858)

  $ cd ..

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate={rev} {desc} {phase}\n
  > EOF


  $ hg init c4
  $ cd c4

  $ echo a > a
  $ hg ci -Am A
  adding a
  $ echo b > b
  $ hg ci -Am B
  adding b
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo c > c
  $ hg ci -Am C
  adding c
  created new head
  $ hg up 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m d
  $ hg up 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo e > e
  $ hg ci -Am E
  adding e
  created new head
  $ hg merge 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m F
  $ hg up 3
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo g > g
  $ hg ci -Am G
  adding g
  created new head
  $ echo h > h
  $ hg ci -Am H
  adding h
  $ hg up 5
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo i > i
  $ hg ci -Am I
  adding i

Turn most changeset public

  $ hg ph -p 7

  $ hg heads
  8 I draft
  7 H public
  $ hg log -G
  @  8 I draft
  |
  | o  7 H public
  | |
  | o  6 G public
  | |
  o |  5 F draft
  |\|
  o |  4 E draft
  | |
  | o  3 d public
  |/|
  o |  2 C public
  | |
  | o  1 B public
  |/
  o  0 A public
  

  $ cat > $TESTTMP/checkeditform.sh <<EOF
  > env | grep HGEDITFORM
  > true
  > EOF
  $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg rebase --dest 7 --source 5 -e
  rebasing 5:361a99976cc9 "F"
  HGEDITFORM=rebase.merge
  rebasing 8:326cfedc031c "I" (tip)
  HGEDITFORM=rebase.normal
  saved backup bundle to $TESTTMP/a3/c4/.hg/strip-backup/361a99976cc9-35e980d0-backup.hg (glob)