get_maintainer: add missing documentation for --git-blame-signatures

I really haven't used this option much myself, so feel free to improve on the documentation for it. I just noticed it while inspecting this script for undocumented features.

---
v1 -> v2:
* reword the documentation to be more accurate

v1:
https://lkml.org/lkml/2015/8/19/442

 scripts/get_maintainer.pl | 1 +
 1 file changed, 1 insertion(+)

index 98bae869f6d0..6ba0976e861e 100755
@@ -781,6 +781,7 @@ MAINTAINER field selection options:
     --git-max-maintainers => maximum maintainers to add (default: $email_git_max_maintainers)
     --git-min-percent => minimum percentage of commits required (default: $email_git_min_percent)
     --git-blame => use git blame to find modified commits for patch or file
+    --git-blame-signatures => when used with --git-blame, also include all commit signers
     --git-since => git history to use (default: $email_git_since)
     --hg-since => hg history to use (default: $email_hg_since)
     --interactive => display a menu (mostly useful if used with the --git option)

2.6.0.rc2.230.g3dd15c0

Though it appears that Perl's GetOptions will take either, the latter is not documented in the options listing.

---
new in v2

 scripts/get_maintainer.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 6ba0976e861e..6c307276f3d6 100755
@@ -813,7 +813,7 @@ Other options:
   --help => show this help information
 
 Default options:
-  [--email --nogit --git-fallback --m --n --l --multiline -pattern-depth=0
+  [--email --nogit --git-fallback --m --n --l --multiline --pattern-depth=0
    --remove-duplicates --rolestats]
 
 Notes:

2.6.0.rc2.230.g3dd15c0

Many flag options are boolean and support both a positive and a negative invocation from the command line. Some of these are even mentioned by example (e.g., --nogit is mentioned as a default option), but they aren't explicitly mentioned in the list of options. It happens that some of these are pretty important, as they are default-on, and to turn them off, you have to know about the --no-foo version.

Rather than clutter the whole help text with bracketed '--[no]foo', let's just mention the general rule, a la 'man gcc'.

---
v1 -> v2:
* don't clutter with --[no]foo bracketing; just include this note up front; suggested by Joe

v1:
https://lkml.org/lkml/2015/8/19/441

 scripts/get_maintainer.pl | 3 +++
 1 file changed, 3 insertions(+)

index 6c307276f3d6..13115eab8992 100755
@@ -770,6 +770,9 @@ usage: $P [options] patchfile
        $P [options] -f file|directory
 version: $V
 
+Most options have both positive and negative forms. The negative form of --foo
+is --nofoo.
+
 MAINTAINER field selection options:
   --email => print email address(es) if any
     --git => include recent git \*-by: signers

2.6.0.rc2.230.g3dd15c0

[]

[]

Oh, I completely overlooked the 'Notes' section when doing this :) I was just imitating the placement in 'man gcc', where the note is in the DESCSRIPTION, which comes before all the options. But your suggestion does seem like a good place.

OK, so in the Notes section, there's a form of second-line indentation, so I guess this?

Most options have both positive and negative forms.
The negative forms for --<foo> are --no<foo> and --no-<foo>.

Will do shortly.

Regards,
Brian

I just noticed you included both --no<foo> and --no-<foo>. I didn't even notice that Perl supported both variants here. Good thing the clueless one is writing the documentation! :) Thanks again for the tips.

Brian

We don't consistenly document the default value next to the option listing, but we do have a list of defaults here, so let's keep it up to date.

---
new in v2

 scripts/get_maintainer.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 13115eab8992..17b9eb2fecb1 100755
@@ -816,7 +816,7 @@ Other options:
   --help => show this help information
 
 Default options:
-  [--email --nogit --git-fallback --m --n --l --multiline --pattern-depth=0
+  [--email --nogit --git-fallback --m --r --n --l --multiline --pattern-depth=0
    --remove-duplicates --rolestats]
 
 Notes:

2.6.0.rc2.230.g3dd15c0