ui: add special-purpose atexit functionality
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
$ hg init t
$ cd t
$ mkdir a
$ echo foo > a/a
$ echo bar > a/b
$ hg ci -Am "0"
adding a/a
adding a/b
$ hg co -C 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg mv a b
moving a/a to b/a (glob)
moving a/b to b/b (glob)
$ hg ci -m "1 mv a/ b/"
$ hg co -C 0
2 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo baz > a/c
$ echo quux > a/d
$ hg add a/c
$ hg ci -m "2 add a/c"
created new head
$ hg merge --debug 1
searching for copies back to rev 1
unmatched files in local:
a/c
unmatched files in other:
b/a
b/b
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
src: 'a/a' -> dst: 'b/a'
src: 'a/b' -> dst: 'b/b'
checking for directory renames
discovered dir src: 'a/' -> dst: 'b/'
pending file src: 'a/c' -> dst: 'b/c'
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: f9b20c0d4c51, local: ce36d17b18fb+, remote: 397f8b00a740
a/a: other deleted -> r
removing a/a
a/b: other deleted -> r
removing a/b
b/a: remote created -> g
getting b/a
b/b: remote created -> g
getting b/b
b/c: remote directory rename - move from a/c -> dm
moving a/c to b/c (glob)
3 files updated, 0 files merged, 2 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo a/* b/*
a/d b/a b/b b/c
$ hg st -C
M b/a
M b/b
A b/c
a/c
R a/a
R a/b
R a/c
? a/d
$ hg ci -m "3 merge 2+1"
$ hg debugrename b/c
b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88 (glob)
$ hg co -C 1
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge --debug 2
searching for copies back to rev 1
unmatched files in local:
b/a
b/b
unmatched files in other:
a/c
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
src: 'a/a' -> dst: 'b/a'
src: 'a/b' -> dst: 'b/b'
checking for directory renames
discovered dir src: 'a/' -> dst: 'b/'
pending file src: 'a/c' -> dst: 'b/c'
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: f9b20c0d4c51, local: 397f8b00a740+, remote: ce36d17b18fb
starting 4 threads for background file closing (?)
b/c: local directory rename - get from a/c -> dg
getting a/c to b/c
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo a/* b/*
a/d b/a b/b b/c
$ hg st -C
A b/c
a/c
? a/d
$ hg ci -m "4 merge 1+2"
created new head
$ hg debugrename b/c
b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88 (glob)
Local directory rename with conflicting file added in remote source directory
and untracked in local target directory.
$ hg co -qC 1
$ echo target > b/c
$ hg merge 2
b/c: untracked file differs
abort: untracked files in working directory differ from files in requested revision
[255]
$ cat b/c
target
but it should succeed if the content matches
$ hg cat -r 2 a/c > b/c
$ hg merge 2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st -C
A b/c
a/c
? a/d
Local directory rename with conflicting file added in remote source directory
and committed in local target directory.
$ hg co -qC 1
$ echo target > b/c
$ hg add b/c
$ hg commit -qm 'new file in target directory'
$ hg merge 2
merging b/c and a/c to b/c
warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg st -A
M b/c
a/c
? a/d
? b/c.orig
C b/a
C b/b
$ cat b/c
<<<<<<< working copy: f1c50ca4f127 - test: new file in target directory
target
=======
baz
>>>>>>> merge rev: ce36d17b18fb - test: 2 add a/c
$ rm b/c.orig
Remote directory rename with conflicting file added in remote target directory
and committed in local source directory.
$ hg co -qC 2
$ hg st -A
? a/d
C a/a
C a/b
C a/c
$ hg merge 5
merging a/c and b/c to b/c
warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
2 files updated, 0 files merged, 2 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ hg st -A
M b/a
M b/b
M b/c
a/c
R a/a
R a/b
R a/c
? a/d
? b/c.orig
$ cat b/c
<<<<<<< working copy: ce36d17b18fb - test: 2 add a/c
baz
=======
target
>>>>>>> merge rev: f1c50ca4f127 - test: new file in target directory
Second scenario with two repos:
$ cd ..
$ hg init r1
$ cd r1
$ mkdir a
$ echo foo > a/f
$ hg add a
adding a/f (glob)
$ hg ci -m "a/f == foo"
$ cd ..
$ hg clone r1 r2
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd r2
$ hg mv a b
moving a/f to b/f (glob)
$ echo foo1 > b/f
$ hg ci -m" a -> b, b/f == foo1"
$ cd ..
$ cd r1
$ mkdir a/aa
$ echo bar > a/aa/g
$ hg add a/aa
adding a/aa/g (glob)
$ hg ci -m "a/aa/g"
$ hg pull ../r2
pulling from ../r2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st -C
M b/f
A b/aa/g
a/aa/g
R a/aa/g
R a/f
$ cd ..
Test renames to separate directories
$ hg init a
$ cd a
$ mkdir a
$ touch a/s
$ touch a/t
$ hg ci -Am0
adding a/s
adding a/t
Add more files
$ touch a/s2
$ touch a/t2
$ hg ci -Am1
adding a/s2
adding a/t2
Do moves on a branch
$ hg up 0
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ mkdir s
$ mkdir t
$ hg mv a/s s
$ hg mv a/t t
$ hg ci -Am2
created new head
$ hg st --copies --change .
A s/s
a/s
A t/t
a/t
R a/s
R a/t
Merge shouldn't move s2, t2
$ hg merge
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st --copies
M a/s2
M a/t2
Try the merge in the other direction. It may or may not be appropriate for
status to list copies here.
$ hg up -C 1
4 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg merge
2 files updated, 0 files merged, 2 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg st --copies
M s/s
M t/t
R a/s
R a/t