get_maintainer: remove stray punctuation when cleaning file emails

When parsing emails from .yaml files in particular, stray punctuation
such as a leading '-' can end up in the name.  For example, consider a
common YAML section such as:

  maintainers:
    - devicetree@vger.kernel.org

This would previously be processed by get_maintainer.pl as:

  - <devicetree@vger.kernel.org>

Make the logic in clean_file_emails more robust by deleting any
sub-names which consist of common single punctuation marks before
proceeding to the best-effort name extraction logic.  The output is then
correct:

  devicetree@vger.kernel.org

Some additional comments are added to the function to make things
clearer to future readers.

Link: https://lore.kernel.org/all/0173e76a36b3a9b4e7f324dd3a36fd4a9757f302.camel@perches.com/
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/get_maintainer.pl b/scripts/get_maintainer.pl
index dac38c6..ee1aed7 100755 (executable)
--- a/scripts/get_maintainer.pl
+++ b/scripts/get_maintainer.pl
@@ -2462,11 +2462,17 @@ sub clean_file_emails {
     foreach my $email (@file_emails) {
        $email =~ s/[\(\<\{]{0,1}([A-Za-z0-9_\.\+-]+\@[A-Za-z0-9\.-]+)[\)\>\}]{0,1}/\<$1\>/g;
        my ($name, $address) = parse_email($email);
-       if ($name eq '"[,\.]"') {
-           $name = "";
-       }
 
+       # Strip quotes for easier processing, format_email will add them back
+       $name =~ s/^"(.*)"$/$1/;
+
+       # Split into name-like parts and remove stray punctuation particles
        my @nw = split(/[^\p{L}\'\,\.\+-]/, $name);
+       @nw = grep(!/^[\'\,\.\+-]$/, @nw);
+
+       # Make a best effort to extract the name, and only the name, by taking
+       # only the last two names, or in the case of obvious initials, the last
+       # three names.
        if (@nw > 2) {
            my $first = $nw[@nw - 3];
            my $middle = $nw[@nw - 2];
@@ -2480,18 +2486,16 @@ sub clean_file_emails {
            } else {
                $name = "$middle $last";
            }
+       } else {
+           $name = "@nw";
        }
 
        if (substr($name, -1) =~ /[,\.]/) {
            $name = substr($name, 0, length($name) - 1);
-       } elsif (substr($name, -2) =~ /[,\.]"/) {
-           $name = substr($name, 0, length($name) - 2) . '"';
        }
 
        if (substr($name, 0, 1) =~ /[,\.]/) {
            $name = substr($name, 1, length($name) - 1);
-       } elsif (substr($name, 0, 2) =~ /"[,\.]/) {
-           $name = '"' . substr($name, 2, length($name) - 2);
        }
 
        my $fmt_email = format_email($name, $address, $email_usename);