internals: document CBOR utilization
I spoke with some people at Mozilla about CBOR and they advised me
that we should be careful about the subset of CBOR we use in order
to mitigate security, performance, and compatibility concerns.
This commit establishes a document that attempts to formalize our
use of CBOR.
Its main limitations are on what types are allowed. It explicitly
enumerates which types are supported. Notable missing features
include:
* Indefinite-length arrays and maps
* Text strings (bytes all the way)
* Floats
* Date/time types
* Big integers
* Use of indefinite-length byte strings for map keys, values in
containers.
If we have a need for any of these, we can have a discussion about
them when the time comes.
Differential Revision: https://phab.mercurial-scm.org/D4412
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
>
> [alias]
> tglog = log -G --template "{rev}: {node|short} '{desc}'\n"
>
> [extensions]
> drawdag=$TESTDIR/drawdag.py
> EOF
Rebasing D onto B detaching from C (one commit):
$ hg init a1
$ cd a1
$ hg debugdrawdag <<EOF
> D
> |
> C B
> |/
> A
> EOF
$ hg phase --force --secret D
$ hg rebase -s D -d B
rebasing 3:e7b3f00ed42e "D" (D tip)
saved backup bundle to $TESTTMP/a1/.hg/strip-backup/e7b3f00ed42e-6f368371-rebase.hg
$ hg log -G --template "{rev}:{phase} '{desc}' {branches}\n"
o 3:secret 'D'
|
| o 2:draft 'C'
| |
o | 1:draft 'B'
|/
o 0:draft 'A'
$ hg manifest --rev tip
A
B
D
$ cd ..
Rebasing D onto B detaching from C (two commits):
$ hg init a2
$ cd a2
$ hg debugdrawdag <<EOF
> E
> |
> D
> |
> C B
> |/
> A
> EOF
$ hg rebase -s D -d B
rebasing 3:e7b3f00ed42e "D" (D)
rebasing 4:69a34c08022a "E" (E tip)
saved backup bundle to $TESTTMP/a2/.hg/strip-backup/e7b3f00ed42e-a2ec7cea-rebase.hg
$ hg tglog
o 4: ee79e0744528 'E'
|
o 3: 10530e1d72d9 'D'
|
| o 2: dc0947a82db8 'C'
| |
o | 1: 112478962961 'B'
|/
o 0: 426bada5c675 'A'
$ hg manifest --rev tip
A
B
D
E
$ cd ..
Rebasing C onto B using detach (same as not using it):
$ hg init a3
$ cd a3
$ hg debugdrawdag <<EOF
> D
> |
> C B
> |/
> A
> EOF
$ hg rebase -s C -d B
rebasing 2:dc0947a82db8 "C" (C)
rebasing 3:e7b3f00ed42e "D" (D tip)
saved backup bundle to $TESTTMP/a3/.hg/strip-backup/dc0947a82db8-b8481714-rebase.hg
$ hg tglog
o 3: 7375f3dbfb0f 'D'
|
o 2: bbfdd6cb49aa 'C'
|
o 1: 112478962961 'B'
|
o 0: 426bada5c675 'A'
$ hg manifest --rev tip
A
B
C
D
$ cd ..
Rebasing D onto B detaching from C and collapsing:
$ hg init a4
$ cd a4
$ hg debugdrawdag <<EOF
> E
> |
> D
> |
> C B
> |/
> A
> EOF
$ hg phase --force --secret E
$ hg rebase --collapse -s D -d B
rebasing 3:e7b3f00ed42e "D" (D)
rebasing 4:69a34c08022a "E" (E tip)
saved backup bundle to $TESTTMP/a4/.hg/strip-backup/e7b3f00ed42e-a2ec7cea-rebase.hg
$ hg log -G --template "{rev}:{phase} '{desc}' {branches}\n"
o 3:secret 'Collapsed revision
| * D
| * E'
| o 2:draft 'C'
| |
o | 1:draft 'B'
|/
o 0:draft 'A'
$ hg manifest --rev tip
A
B
D
E
$ cd ..
Rebasing across null as ancestor
$ hg init a5
$ cd a5
$ hg debugdrawdag <<EOF
> E
> |
> D
> |
> C
> |
> A B
> EOF
$ hg rebase -s C -d B
rebasing 2:dc0947a82db8 "C" (C)
rebasing 3:e7b3f00ed42e "D" (D)
rebasing 4:69a34c08022a "E" (E tip)
saved backup bundle to $TESTTMP/a5/.hg/strip-backup/dc0947a82db8-3eefec98-rebase.hg
$ hg tglog
o 4: e3d0c70d606d 'E'
|
o 3: e9153d36a1af 'D'
|
o 2: a7ac28b870a8 'C'
|
o 1: fc2b737bb2e5 'B'
o 0: 426bada5c675 'A'
$ hg rebase -d 1 -s 3
rebasing 3:e9153d36a1af "D"
rebasing 4:e3d0c70d606d "E" (tip)
saved backup bundle to $TESTTMP/a5/.hg/strip-backup/e9153d36a1af-db7388ed-rebase.hg
$ hg tglog
o 4: 2c24e540eccd 'E'
|
o 3: 73f786ed52ff 'D'
|
| o 2: a7ac28b870a8 'C'
|/
o 1: fc2b737bb2e5 'B'
o 0: 426bada5c675 'A'
$ cd ..
Verify that target is not selected as external rev (issue3085)
$ hg init a6
$ cd a6
$ hg debugdrawdag <<EOF
> H
> | G
> |/|
> F E
> |/
> A
> EOF
$ hg up -q G
$ echo "I" >> E
$ hg ci -m "I"
$ hg tag --local I
$ hg merge H
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m "Merge"
$ echo "J" >> F
$ hg ci -m "J"
$ hg tglog
@ 7: c6aaf0d259c0 'J'
|
o 6: 0cfbc7e8faaf 'Merge'
|\
| o 5: b92d164ad3cb 'I'
| |
o | 4: 4ea5b230dea3 'H'
| |
| o 3: c6001eacfde5 'G'
|/|
o | 2: 8908a377a434 'F'
| |
| o 1: 7fb047a69f22 'E'
|/
o 0: 426bada5c675 'A'
$ hg rebase -s I -d H --collapse --config ui.merge=internal:other
rebasing 5:b92d164ad3cb "I" (I)
rebasing 6:0cfbc7e8faaf "Merge"
rebasing 7:c6aaf0d259c0 "J" (tip)
saved backup bundle to $TESTTMP/a6/.hg/strip-backup/b92d164ad3cb-88fd7ab7-rebase.hg
$ hg tglog
@ 5: 65079693dac4 'Collapsed revision
| * I
| * Merge
| * J'
o 4: 4ea5b230dea3 'H'
|
| o 3: c6001eacfde5 'G'
|/|
o | 2: 8908a377a434 'F'
| |
| o 1: 7fb047a69f22 'E'
|/
o 0: 426bada5c675 'A'
$ hg log --rev tip
changeset: 5:65079693dac4
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Collapsed revision
$ cd ..
Ensure --continue restores a correct state (issue3046) and phase:
$ hg init a7
$ cd a7
$ hg debugdrawdag <<EOF
> C B
> |/
> A
> EOF
$ hg up -q C
$ echo 'B2' > B
$ hg ci -A -m 'B2'
adding B
$ hg phase --force --secret .
$ hg rebase -s . -d B --config ui.merge=internal:fail
rebasing 3:17b4880d2402 "B2" (tip)
merging B
warning: conflicts while merging B! (edit, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
$ hg resolve --all -t internal:local
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase -c
rebasing 3:17b4880d2402 "B2" (tip)
note: rebase of 3:17b4880d2402 created no changes to commit
saved backup bundle to $TESTTMP/a7/.hg/strip-backup/17b4880d2402-1ae1f6cc-rebase.hg
$ hg log -G --template "{rev}:{phase} '{desc}' {branches}\n"
o 2:draft 'C'
|
| @ 1:draft 'B'
|/
o 0:draft 'A'
$ cd ..