Re: [PATCH v6] Add new git-related helper to contrib

> Felipe Contreras <felipe.contreras@gmail.com> writes:
>
>> diff --git a/contrib/related/git-related b/contrib/related/git-related
>> new file mode 100755
>> index 0000000..b96dcdd
>> --- /dev/null
>> +++ b/contrib/related/git-related
>> @@ -0,0 +1,124 @@
>> +#!/usr/bin/env ruby
>> +
>> +# This script finds people that might be interested in a patch
>> +# usage: git related <file>
>> +
>> +$since = '5-years-ago'
>> +$min_percent = 10
>> +
>> +def fmt_person(name, email)
>> +  '%s <%s>' % [name, email]
>> +end
>
> Micronit.  I suspect you do not need this helper, unless later
> patches start using it.

>> +  def import
>> +    return if @items.empty?
>> +    File.popen(%w[git cat-file --batch], 'r+') do |p|
>> +      p.write(@items.keys.join("\n"))
>> +      p.close_write
>> +      p.each do |line|
>> +        if line =~ /^(\h{40}) commit (\d+)/
>> +          id, len = $1, $2
>> +          data = p.read($2.to_i)
>> +          @items[id].parse(data)
>> +        end
>> +      end
>> +    end
>> +  end
>> +
>> +  def get_blame(source, start, len, from)
>> +    return if len == 0
>> +    len ||= 1
>> +    File.popen(['git', 'blame', '--incremental', '-CCC',
>
> I am torn on the hardcoded use of "-CCC" here.
>
> Depending on the nature of the change in question, it may match well
> or worse to what you are trying to find out.  When you are trying to
> say "What were you smoking when you implemented this broken logic?",
> using -C may be good, but when your question is "Even though all the
> callers of this function live in that other file, somebody moved
> this function that used to be file static in that file to here and
> made it public. Why?", you do not want to use -C.
>
> I am reasonably sure that in the finished code later in the series
> it will become configurable, but a fallback default is better to be
> not so expensive one.

>> +               '-L', '%u,+%u' % [start, len],
>> +               '--since', $since, from + '^',
>
> Is "from" unconditionally set?
>
> Perhaps that nil + '^' magically disappear and this code is relying
> on that, but it smells like a too much magic to me.

>> +               '--', source]) do |p|
>> +      p.each do |line|
>> +        if line =~ /^(\h{40})/
>> +          id = $&
>> +          @items[id] = Commit.new(id)
>> +        end
>> +      end
>> +    end
>> +  end
>> +
>> +  def from_patch(file)
>> +    from = source = nil
>> +    File.open(file) do |f|
>> +      f.each do |line|
>> +        case line
>> +        when /^From (\h+) (.+)$/
>> +          from = $1
>> +        when /^---\s+(\S+)/
>> +          source = $1 != '/dev/null' ? $1[2..-1] : nil
>> +        when /^@@ -(\d+)(?:,(\d+))?/
>> +          get_blame(source, $1, $2, from)
>> +        end
>
> Makes sense to start from the preimage so that you can find out who
> wrote the original block of lines your patch is removing.
>
> But then if source is /dev/null, wouldn't you be able to stop
> without running blame at all?  You know the patch is creating a new
> file at that point and there is nobody to point a finger at.