revset: use decorator to register a function as revset predicate
Using decorator can localize changes for adding (or removing) a revset
predicate function in source code.
It is also useful to pick predicates up for specific purpose. For
example, subsequent patch marks predicates as "safe" by decorator.
This patch defines 'parsefuncdecl()' in 'funcregistrar' class, because
this implementation can be uesd by other decorator class for fileset
predicate and template function.
$ hg init
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ hg update 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo This is file c1 > c
$ hg add c
$ hg commit -m "commit #2"
created new head
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ rm b
$ echo This is file c22 > c
Test hg behaves when committing with a missing file added by a merge
$ hg commit -m "commit #3"
abort: cannot commit merge with missing files
[255]