show: use consistent (and possibly shorter) node lengths
`hg show` makes heavy use of shortest() to limit the length of the node
hash.
For the "stack" and "work" views, you are often looking at multiple
lines of similar output for "lines" of work. It is visually appeasing
for things to vertically align. A naive use of {shortest(node, N)}
could result in variable length nodes and for the first character of
the description to vary by a column or two.
We implement a function to determine the longest shortest prefix for
a set of revisions. The new function is used to determine the printed
node length for all `hg show` views.
.. feature::
show: use consistent node length in views
Our previous shortest node length of 5 was arbitrarily chosen.
shortest() already does the work of ensuring that a partial node
isn't ambiguous with an integer revision, which is our primary risk
of a collision for very short nodes. It should be safe to go with the
shortest node possible.
Existing code is also optimized to handle nodes as short as 4.
So, we decrease the minimum hash length from 5 to 4.
We also add a test demonstrating that prefix collisions increase the
node length.
.. feature::
show: decrease minimum displayed hash length from 5 to 4
Differential Revision: https://phab.mercurial-scm.org/D558
$ cat >> $HGRCPATH << EOF
> [extensions]
> show =
> EOF
No arguments shows available views
$ hg init empty
$ cd empty
$ hg show
available views:
bookmarks -- bookmarks and their associated changeset
stack -- current line of work
work -- changesets that aren't finished
abort: no view requested
(use "hg show VIEW" to choose a view)
[255]
`hg help show` prints available views
$ hg help show
hg show VIEW
show various repository information
A requested view of repository data is displayed.
If no view is requested, the list of available views is shown and the
command aborts.
Note:
There are no backwards compatibility guarantees for the output of this
command. Output may change in any future Mercurial release.
Consumers wanting stable command output should specify a template via
"-T/--template".
List of available views:
bookmarks bookmarks and their associated changeset
stack current line of work
work changesets that aren't finished
(use 'hg help -e show' to show help for the show extension)
options:
-T --template TEMPLATE display with template
(some details hidden, use --verbose to show complete help)
Unknown view prints error
$ hg show badview
abort: unknown view: badview
(run "hg show" to see available views)
[255]
HGPLAIN results in abort
$ HGPLAIN=1 hg show bookmarks
abort: must specify a template in plain mode
(invoke with -T/--template to control output format)
[255]
But not if a template is specified
$ HGPLAIN=1 hg show bookmarks -T '{bookmark}\n'
(no bookmarks set)
$ cd ..
bookmarks view with no bookmarks prints empty message
$ hg init books
$ cd books
$ touch f0
$ hg -q commit -A -m initial
$ hg show bookmarks
(no bookmarks set)
bookmarks view shows bookmarks in an aligned table
$ echo book1 > f0
$ hg commit -m 'commit for book1'
$ echo book2 > f0
$ hg commit -m 'commit for book2'
$ hg bookmark -r 1 book1
$ hg bookmark a-longer-bookmark
$ hg show bookmarks
* a-longer-bookmark 7b57
book1 b757
A custom bookmarks template works
$ hg show bookmarks -T '{node} {bookmark} {active}\n'
7b5709ab64cbc34da9b4367b64afff47f2c4ee83 a-longer-bookmark True
b757f780b8ffd71267c6ccb32e0882d9d32a8cc0 book1 False
bookmarks JSON works
$ hg show bookmarks -T json
[
{
"active": true,
"bookmark": "a-longer-bookmark",
"longestbookmarklen": 17,
"node": "7b5709ab64cbc34da9b4367b64afff47f2c4ee83",
"nodelen": 4
},
{
"active": false,
"bookmark": "book1",
"longestbookmarklen": 17,
"node": "b757f780b8ffd71267c6ccb32e0882d9d32a8cc0",
"nodelen": 4
}
]
JSON works with no bookmarks
$ hg book -d a-longer-bookmark
$ hg book -d book1
$ hg show bookmarks -T json
[
]
commands.show.aliasprefix aliases values to `show <view>`
$ hg --config commands.show.aliasprefix=s sbookmarks
(no bookmarks set)
$ hg --config commands.show.aliasprefix=sh shwork
@ 7b57 commit for book2
o b757 commit for book1
o ba59 initial
$ hg --config commands.show.aliasprefix='s sh' swork
@ 7b57 commit for book2
o b757 commit for book1
o ba59 initial
$ hg --config commands.show.aliasprefix='s sh' shwork
@ 7b57 commit for book2
o b757 commit for book1
o ba59 initial
The aliases don't appear in `hg config`
$ hg --config commands.show.aliasprefix=s config alias
[1]
Doesn't overwrite existing alias
$ hg --config alias.swork='log -r .' --config commands.show.aliasprefix=s swork
changeset: 2:7b5709ab64cb
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: commit for book2
$ hg --config alias.swork='log -r .' --config commands.show.aliasprefix=s config alias
alias.swork=log -r .
$ cd ..