doc: add note about pattern rooted/unrooted cases to "hgignore" and "patterns"
each help topics describe that patterns are "not rooted" and "rooted"
in themselves, but not describe about each other.
so, this may causes misunderstanding about "rooted"-ness of patterns.
Mercurial accepts several notations for identifying one or more files
at a time.
By default, Mercurial treats filenames as shell-style extended glob
patterns.
Alternate pattern notations must be specified explicitly.
.. note::
Patterns specified in ``.hgignore`` are not rooted. Please see
:hg:`help hgignore` for details.
To use a plain path name without any pattern matching, start it with
``path:``. These path names must completely match starting at the
current repository root.
To use an extended glob, start a name with ``glob:``. Globs are rooted
at the current directory; a glob such as ``*.c`` will only match files
in the current directory ending with ``.c``.
The supported glob syntax extensions are ``**`` to match any string
across path separators and ``{a,b}`` to mean "a or b".
To use a Perl/Python regular expression, start a name with ``re:``.
Regexp pattern matching is anchored at the root of the repository.
To read name patterns from a file, use ``listfile:`` or ``listfile0:``.
The latter expects null delimited patterns while the former expects line
feeds. Each string read from the file is itself treated as a file
pattern.
Plain examples::
path:foo/bar a name bar in a directory named foo in the root
of the repository
path:path:name a file or directory named "path:name"
Glob examples::
glob:*.c any name ending in ".c" in the current directory
*.c any name ending in ".c" in the current directory
**.c any name ending in ".c" in any subdirectory of the
current directory including itself.
foo/*.c any name ending in ".c" in the directory foo
foo/**.c any name ending in ".c" in any subdirectory of foo
including itself.
Regexp examples::
re:.*\.c$ any name ending in ".c", anywhere in the repository
File examples::
listfile:list.txt read list from list.txt with one file pattern per line
listfile0:list.txt read list from list.txt with null byte delimiters
See also :hg:`help filesets`.