Mercurial > hg
view tests/test-issue3084.t @ 23702:c48924787eaa
filectx.parents: enforce changeid of parent to be in own changectx ancestors
Because of the way filenodes are computed, you can have multiple changesets
"introducing" the same file revision. For example, in the changeset graph
below, changeset 2 and 3 both change a file -to- and -from- the same content.
o 3: content = new
|
| o 2: content = new
|/
o 1: content = old
In such cases, the file revision is create once, when 2 is added, and just reused
for 3. So the file change in '3' (from "old" to "new)" has no linkrev pointing
to it). We'll call this situation "linkrev-shadowing". As the linkrev is used for
optimization purposes when walking a file history, the linkrev-shadowing
results in an unexpected jump to another branch during such a walk.. This leads to
multiple bugs with log, annotate and rename detection.
One element to fix such bugs is to ensure that walking the file history sticks on
the same topology as the changeset's history. For this purpose, we extend the
logic in 'basefilectx.parents' so that it always defines the proper changeset
to associate the parent file revision with. This "proper" changeset has to be an
ancestor of the changeset associated with the child file revision.
This logic is performed in the '_adjustlinkrev' function. This function is
given the starting changeset and all the information regarding the parent file
revision. If the linkrev for the file revision is an ancestor of the starting
changeset, the linkrev is valid and will be used. If it is not, we detected a
topological jump caused by linkrev shadowing, we are going to walk the
ancestors of the starting changeset until we find one setting the file to the
revision we are trying to create.
The performance impact appears acceptable:
- We are walking the changelog once for each filelog traversal (as there should
be no overlap between searches),
- changelog traversal itself is fairly cheap, compared to what is likely going
to be perform on the result on the filelog traversal,
- We only touch the manifest for ancestors touching the file, And such
changesets are likely to be the one introducing the file. (except in
pathological cases involving merge),
- We use manifest diff instead of full manifest unpacking to check manifest
content, so it does not involve applying multiple diffs in most case.
- linkrev shadowing is not the common case.
Tests for fixed issues in log, annotate and rename detection have been
added.
But this changeset does not solve all problems. It fixes -ancestry-
computation, but if the linkrev-shadowed changesets is the starting one, we'll
still get things wrong. We'll have to fix the bootstrapping of such operations
in a later changeset. Also, the usage of `hg log FILE` without --follow still
has issues with linkrev pointing to hidden changesets, because it relies on the
`filelog` revset which implement its own traversal logic that is still to be
fixed.
Thanks goes to:
- Matt Mackall: for nudging me in the right direction
- Julien Cristau and RĂ©mi Cardona: for keep telling me linkrev bug were an
evolution show stopper for 3 years.
- Durham Goode: for finding a new linkrev issue every few weeks
- Mads Kiilerich: for that last rename bug who raise this topic over my
anoyance limit.
author | Pierre-Yves David <pierre-yves.david@fb.com> |
---|---|
date | Tue, 23 Dec 2014 15:30:38 -0800 |
parents | 495bc1b65d25 |
children | 9d5c27890790 |
line wrap: on
line source
$ echo "[extensions]" >> $HGRCPATH $ echo "largefiles =" >> $HGRCPATH Create the repository outside $HOME since largefiles write to $HOME/.cache/largefiles. $ hg init test $ cd test $ echo "root" > root $ hg add root $ hg commit -m "Root commit" --config extensions.largefiles=! Ensure that .hg/largefiles isn't created before largefiles are added #if unix-permissions $ chmod 555 .hg #endif $ hg status #if unix-permissions $ chmod 755 .hg #endif $ test -f .hg/largefiles [1] $ echo "large" > foo $ hg add --large foo $ hg commit -m "Add foo as a largefile" $ hg update -r 0 getting changed largefiles 0 largefiles updated, 1 removed 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo "normal" > foo $ hg add foo $ hg commit -m "Add foo as normal file" created new head Normal file in the working copy, keeping the normal version: $ echo "n" | hg merge --config ui.interactive=Yes remote turned local normal file foo into a largefile use (l)argefile or keep (n)ormal file? n 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg status $ cat foo normal Normal file in the working copy, keeping the largefile version: $ hg update -q -C $ echo "l" | hg merge --config ui.interactive=Yes remote turned local normal file foo into a largefile use (l)argefile or keep (n)ormal file? l getting changed largefiles 1 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg status M foo $ hg diff --nodates diff -r fa129ab6b5a7 .hglf/foo --- /dev/null +++ b/.hglf/foo @@ -0,0 +1,1 @@ +7f7097b041ccf68cc5561e9600da4655d21c6d18 diff -r fa129ab6b5a7 foo --- a/foo +++ /dev/null @@ -1,1 +0,0 @@ -normal $ cat foo large Largefile in the working copy, keeping the normal version: $ hg update -q -C -r 1 $ echo "n" | hg merge --config ui.interactive=Yes remote turned local largefile foo into a normal file keep (l)argefile or use (n)ormal file? n getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg status M foo $ hg diff --nodates diff -r ff521236428a .hglf/foo --- a/.hglf/foo +++ /dev/null @@ -1,1 +0,0 @@ -7f7097b041ccf68cc5561e9600da4655d21c6d18 diff -r ff521236428a foo --- /dev/null +++ b/foo @@ -0,0 +1,1 @@ +normal $ cat foo normal Largefile in the working copy, keeping the largefile version: $ hg update -q -C -r 1 $ echo "l" | hg merge --config ui.interactive=Yes remote turned local largefile foo into a normal file keep (l)argefile or use (n)ormal file? l getting changed largefiles 0 largefiles updated, 0 removed 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg status $ cat foo large Whatever ... commit something so we can invoke merge when updating $ hg commit -m '3: Merge' Updating from largefile to normal - no reason to prompt $ hg up -r 2 getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ cat foo normal (the update above used to leave the working dir in a very weird state - clean it $ hg up -qr null $ hg up -qr 2 ) Updating from normal to largefile - no reason to prompt $ hg up -r 3 getting changed largefiles 1 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ cat foo large $ cd .. Systematic testing of merges involving largefiles: Ancestor: normal Parent: normal-id Parent: large result: large Ancestor: normal Parent: normal2 Parent: large result: ? Ancestor: large Parent: large-id Parent: normal result: normal Ancestor: large Parent: large2 Parent: normal result: ? All cases should try merging both ways. Prepare test repo: $ hg init merges $ cd merges prepare cases with "normal" ancestor: $ hg up -qr null $ echo normal > f $ hg ci -Aqm "normal-ancestor" $ hg tag -l "normal-ancestor" $ touch f2 $ hg ci -Aqm "normal-id" $ hg tag -l "normal-id" $ echo normal2 > f $ hg ci -m "normal2" $ hg tag -l "normal2" $ echo normal > f $ hg ci -Aqm "normal-same" $ hg tag -l "normal-same" $ hg up -qr "normal-ancestor" $ hg rm f $ echo large > f $ hg add --large f $ hg ci -qm "large" $ hg tag -l "large" prepare cases with "large" ancestor: $ hg up -qr null $ echo large > f $ hg add --large f $ hg ci -qm "large-ancestor" $ hg tag -l "large-ancestor" $ touch f2 $ hg ci -Aqm "large-id" $ hg tag -l "large-id" $ echo large2 > f $ hg ci -m "large2" $ hg tag -l "large2" $ echo large > f $ hg ci -Aqm "large-same" $ hg tag -l "large-same" $ hg up -qr "large-ancestor" $ hg rm f $ echo normal > f $ hg ci -qAm "normal" $ hg tag -l "normal" $ hg log -GT '{tags}' @ normal tip | | o large-same | | | o large2 | | | o large-id |/ o large-ancestor o large | | o normal-same | | | o normal2 | | | o normal-id |/ o normal-ancestor Ancestor: normal Parent: normal-id Parent: large result: large $ hg up -Cqr normal-id $ hg merge -r large getting changed largefiles 1 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large swap $ hg up -Cqr large $ hg merge -r normal-id getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large Ancestor: normal Parent: normal-same Parent: large result: large $ hg up -Cqr normal-same $ hg merge -r large getting changed largefiles 1 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large swap $ hg up -Cqr large $ hg merge -r normal-same getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large Ancestor: normal Parent: normal2 Parent: large result: ? (annoying extra prompt ... but it do not do any serious harm) $ hg up -Cqr normal2 $ hg merge -r large remote turned local normal file f into a largefile use (l)argefile or keep (n)ormal file? l getting changed largefiles 1 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large $ hg up -Cqr normal2 $ echo n | hg merge -r large --config ui.interactive=Yes remote turned local normal file f into a largefile use (l)argefile or keep (n)ormal file? n 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal2 swap $ hg up -Cqr large $ hg merge -r normal2 remote turned local largefile f into a normal file keep (l)argefile or use (n)ormal file? l getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large $ hg up -Cqr large $ echo n | hg merge -r normal2 --config ui.interactive=Yes remote turned local largefile f into a normal file keep (l)argefile or use (n)ormal file? n getting changed largefiles 0 largefiles updated, 0 removed 2 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal2 Ancestor: large Parent: large-id Parent: normal result: normal $ hg up -Cqr large-id $ hg merge -r normal getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal swap $ hg up -Cqr normal $ hg merge -r large-id 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal Ancestor: large Parent: large-same Parent: normal result: normal $ hg up -Cqr large-same $ hg merge -r normal getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal swap $ hg up -Cqr normal $ hg merge -r large-same 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal Ancestor: large Parent: large2 Parent: normal result: ? (annoying extra prompt ... but it do not do any serious harm) $ hg up -Cqr large2 $ hg merge -r normal remote turned local largefile f into a normal file keep (l)argefile or use (n)ormal file? l getting changed largefiles 0 largefiles updated, 0 removed 0 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large2 $ hg up -Cqr large2 $ echo n | hg merge -r normal --config ui.interactive=Yes remote turned local largefile f into a normal file keep (l)argefile or use (n)ormal file? n getting changed largefiles 0 largefiles updated, 0 removed 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal swap $ hg up -Cqr normal $ hg merge -r large2 remote turned local normal file f into a largefile use (l)argefile or keep (n)ormal file? l getting changed largefiles 1 largefiles updated, 0 removed 2 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f large2 $ hg up -Cqr normal $ echo n | hg merge -r large2 --config ui.interactive=Yes remote turned local normal file f into a largefile use (l)argefile or keep (n)ormal file? n 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat f normal $ cd ..