[PATCH 5 of 9] grep: correctly handle multiline matches with several expressions

[Pierre-Yves David]

On Sun, Oct 14, 2012 at 10:54:22PM +0200, Idan Kamara wrote:
> # HG changeset patch
> # User Idan Kamara <idankk86 at gmail.com>
> # Date 1349693025 -7200
> # Node ID a83911a11e922e7b941e1c1dd6c66a6654a6b069
> # Parent  06edbeb509881597122b46de831da4332076c4a1
> grep: correctly handle multiline matches with several expressions

This changesets add non-trivial logic and should be better described

> 
> diff --git a/mercurial/commands.py b/mercurial/commands.py
> --- a/mercurial/commands.py
> +++ b/mercurial/commands.py
> @@ -2953,6 +2953,17 @@
>              lstart = body.rfind('\n', begin, mstart) + 1 or begin
>              begin = body.find('\n', mend) + 1 or len(body) + 1
>              lend = begin - 1
> +            # We need to be careful with multiline regexps. Since we pick
> +            # the match that is seen earlier in the file, it's possible
> +            # that a multiline regexp spans the same line as the match we
> +            # picked but includes the following lines. In that case we'd like
> +            # to pick the longer regexp.

This comment is welcome, but the exacte trouble we want to avoid is not cristal clear (see below)

> +            for m in matches:
> +                if m != match:
> +                    s, e = m.span()
> +                    if lstart <= s <= lend and e > lend:
> +                        begin = body.find('\n', e) + 1 or len(body) + 1
> +                        lend = begin - 1
>              yield linenum, mstart - lstart, mend - lstart, body[lstart:lend]
>  
>      class linestate(object):
> diff --git a/tests/test-grep.t b/tests/test-grep.t
> --- a/tests/test-grep.t
> +++ b/tests/test-grep.t
> @@ -31,6 +31,9 @@
>    port:4:export
>    port:4:vaportight
>    port:4:import/export
> +  $ hg grep -e vap -e 'ght\nimp' port
> +  port:4:vaportight
> +  import/export
>    $ hg grep --no-filename port port
>    4:export
>    4:vaportight

What about your document this testcase a bit more? We example output of what we
are trying to avoid.


-- 
Pierre-Yves David

http://www.logilab.fr/

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