rebase: turn rebaseskipobsolete on by default
Consider the following use case. User has a set of commits he wants to rebase
onto some destination. Some of the commits in the set are already rebased
and their new versions are now among the ancestors of destination. Traditional
rebase behavior would make the rebase and effectively try to apply older
versions of these commits on top of newer versions, like this:
a` --> b --> a`
(where both 'a`' and 'a``' are rebased versions of 'a')
This is not desired since 'b' might have made changes to 'a`' which can now
result in merge conflicts. We can avoid these merge conflicts since we know
that 'a``' is an older version of 'a`', so we don't even need to put it on top
of 'b'. Rebaseskipobsolete allows us to do exactly that.
Another undesired effect of a pure rebase is that now 'a`' and 'a``' are both
successors to 'a' which is a divergence. We don't want that and not rebasing
'a' the second time allows to avoid it.
This was not enabled by default initially because we wanted to have some more
experience with it. After months of painless usages in multiple places, we are
confident enough to turn it on my default.
Mercurial supports a functional language for selecting a set of
revisions.
The language supports a number of predicates which are joined by infix
operators. Parenthesis can be used for grouping.
Identifiers such as branch names may need quoting with single or
double quotes if they contain characters like ``-`` or if they match
one of the predefined predicates.
Special characters can be used in quoted identifiers by escaping them,
e.g., ``\n`` is interpreted as a newline. To prevent them from being
interpreted, strings can be prefixed with ``r``, e.g. ``r'...'``.
There is a single prefix operator:
``not x``
Changesets not in x. Short form is ``! x``.
These are the supported infix operators:
``x::y``
A DAG range, meaning all changesets that are descendants of x and
ancestors of y, including x and y themselves. If the first endpoint
is left out, this is equivalent to ``ancestors(y)``, if the second
is left out it is equivalent to ``descendants(x)``.
An alternative syntax is ``x..y``.
``x:y``
All changesets with revision numbers between x and y, both
inclusive. Either endpoint can be left out, they default to 0 and
tip.
``x and y``
The intersection of changesets in x and y. Short form is ``x & y``.
``x or y``
The union of changesets in x and y. There are two alternative short
forms: ``x | y`` and ``x + y``.
``x - y``
Changesets in x but not in y.
``x^n``
The nth parent of x, n == 0, 1, or 2.
For n == 0, x; for n == 1, the first parent of each changeset in x;
for n == 2, the second parent of changeset in x.
``x~n``
The nth first ancestor of x; ``x~0`` is x; ``x~3`` is ``x^^^``.
There is a single postfix operator:
``x^``
Equivalent to ``x^1``, the first parent of each changeset in x.
The following predicates are supported:
.. predicatesmarker
New predicates (known as "aliases") can be defined, using any combination of
existing predicates or other aliases. An alias definition looks like::
<alias> = <definition>
in the ``revsetalias`` section of a Mercurial configuration file. Arguments
of the form `$1`, `$2`, etc. are substituted from the alias into the
definition.
For example,
::
[revsetalias]
h = heads()
d($1) = sort($1, date)
rs($1, $2) = reverse(sort($1, $2))
defines three aliases, ``h``, ``d``, and ``rs``. ``rs(0:tip, author)`` is
exactly equivalent to ``reverse(sort(0:tip, author))``.
An infix operator ``##`` can concatenate strings and identifiers into
one string. For example::
[revsetalias]
issue($1) = grep(r'\bissue[ :]?' ## $1 ## r'\b|\bbug\(' ## $1 ## r'\)')
``issue(1234)`` is equivalent to ``grep(r'\bissue[ :]?1234\b|\bbug\(1234\)')``
in this case. This matches against all of "issue 1234", "issue:1234",
"issue1234" and "bug(1234)".
All other prefix, infix and postfix operators have lower priority than
``##``. For example, ``$1 ## $2~2`` is equivalent to ``($1 ## $2)~2``.
Command line equivalents for :hg:`log`::
-f -> ::.
-d x -> date(x)
-k x -> keyword(x)
-m -> merge()
-u x -> user(x)
-b x -> branch(x)
-P x -> !::x
-l x -> limit(expr, x)
Some sample queries:
- Changesets on the default branch::
hg log -r "branch(default)"
- Changesets on the default branch since tag 1.5 (excluding merges)::
hg log -r "branch(default) and 1.5:: and not merge()"
- Open branch heads::
hg log -r "head() and not closed()"
- Changesets between tags 1.3 and 1.5 mentioning "bug" that affect
``hgext/*``::
hg log -r "1.3::1.5 and keyword(bug) and file('hgext/*')"
- Changesets committed in May 2008, sorted by user::
hg log -r "sort(date('May 2008'), user)"
- Changesets mentioning "bug" or "issue" that are not in a tagged
release::
hg log -r "(keyword(bug) or keyword(issue)) and not ancestors(tag())"