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
hide outer repo
$ hg init
Invalid syntax: no value
$ cat > .hg/hgrc << EOF
> novaluekey
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: novaluekey
[255]
Invalid syntax: no key
$ cat > .hg/hgrc << EOF
> =nokeyvalue
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: =nokeyvalue
[255]
Test hint about invalid syntax from leading white space
$ cat > .hg/hgrc << EOF
> key=value
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: key=value
unexpected leading whitespace
[255]
$ cat > .hg/hgrc << EOF
> [section]
> key=value
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: [section]
unexpected leading whitespace
[255]
Reset hgrc
$ echo > .hg/hgrc
Test case sensitive configuration
$ cat <<EOF >> $HGRCPATH
> [Section]
> KeY = Case Sensitive
> key = lower case
> EOF
$ hg showconfig Section
Section.KeY=Case Sensitive
Section.key=lower case
$ hg showconfig Section -Tjson
[
{
"name": "Section.KeY",
"source": "*.hgrc:*", (glob)
"value": "Case Sensitive"
},
{
"name": "Section.key",
"source": "*.hgrc:*", (glob)
"value": "lower case"
}
]
$ hg showconfig Section.KeY -Tjson
[
{
"name": "Section.KeY",
"source": "*.hgrc:*", (glob)
"value": "Case Sensitive"
}
]
$ hg showconfig -Tjson | tail -7
},
{
"name": "*", (glob)
"source": "*", (glob)
"value": "*" (glob)
}
]
Test empty config source:
$ cat <<EOF > emptysource.py
> def reposetup(ui, repo):
> ui.setconfig(b'empty', b'source', b'value')
> EOF
$ cp .hg/hgrc .hg/hgrc.orig
$ cat <<EOF >> .hg/hgrc
> [extensions]
> emptysource = `pwd`/emptysource.py
> EOF
$ hg config --debug empty.source
read config from: * (glob)
none: value
$ hg config empty.source -Tjson
[
{
"name": "empty.source",
"source": "",
"value": "value"
}
]
$ cp .hg/hgrc.orig .hg/hgrc
Test "%unset"
$ cat >> $HGRCPATH <<EOF
> [unsettest]
> local-hgrcpath = should be unset (HGRCPATH)
> %unset local-hgrcpath
>
> global = should be unset (HGRCPATH)
>
> both = should be unset (HGRCPATH)
>
> set-after-unset = should be unset (HGRCPATH)
> EOF
$ cat >> .hg/hgrc <<EOF
> [unsettest]
> local-hgrc = should be unset (.hg/hgrc)
> %unset local-hgrc
>
> %unset global
>
> both = should be unset (.hg/hgrc)
> %unset both
>
> set-after-unset = should be unset (.hg/hgrc)
> %unset set-after-unset
> set-after-unset = should be set (.hg/hgrc)
> EOF
$ hg showconfig unsettest
unsettest.set-after-unset=should be set (.hg/hgrc)
Test exit code when no config matches
$ hg config Section.idontexist
[1]
sub-options in [paths] aren't expanded
$ cat > .hg/hgrc << EOF
> [paths]
> foo = ~/foo
> foo:suboption = ~/foo
> EOF
$ hg showconfig paths
paths.foo:suboption=~/foo
paths.foo=$TESTTMP/foo
edit failure
$ HGEDITOR=false hg config --edit
abort: edit failed: false exited with status 1
[255]
config affected by environment variables
$ EDITOR=e1 VISUAL=e2 hg config --debug | grep 'ui\.editor'
$VISUAL: ui.editor=e2
$ VISUAL=e2 hg config --debug --config ui.editor=e3 | grep 'ui\.editor'
--config: ui.editor=e3
$ PAGER=p1 hg config --debug | grep 'pager\.pager'
$PAGER: pager.pager=p1
$ PAGER=p1 hg config --debug --config pager.pager=p2 | grep 'pager\.pager'
--config: pager.pager=p2
verify that aliases are evaluated as well
$ hg init aliastest
$ cd aliastest
$ cat > .hg/hgrc << EOF
> [ui]
> user = repo user
> EOF
$ touch index
$ unset HGUSER
$ hg ci -Am test
adding index
$ hg log --template '{author}\n'
repo user
$ cd ..
alias has lower priority
$ hg init aliaspriority
$ cd aliaspriority
$ cat > .hg/hgrc << EOF
> [ui]
> user = alias user
> username = repo user
> EOF
$ touch index
$ unset HGUSER
$ hg ci -Am test
adding index
$ hg log --template '{author}\n'
repo user
$ cd ..