checkpatch: improve --git <commit-count> shortcut

The --git <commit-count> shortcut can be confused by a tag with a dash
like v4.4-rc1.

Improve the test to verify the <commit-count> expression ends with a
dash followed by a numeric value.

Improve the git log result to verify the "<sha1> <subject>" output
as well.

Link: http://lkml.kernel.org/r/c4a3f759291d967641860c3a54bb81177f34325f.1462711962.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 9283662..6750595 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -809,11 +809,8 @@ if ($git) {
        my @commits = ();
        foreach my $commit_expr (@ARGV) {
                my $git_range;
-               if ($commit_expr =~ m/-/) {
-                       my @tmp = split(/-/, $commit_expr);
-                       die "$P: incorrect git commit expression '$commit_expr' $!\n"
-                           if (@tmp != 2);
-                       $git_range = "-$tmp[1] $tmp[0]";
+               if ($commit_expr =~ m/^(.*)-(\d+)$/) {
+                       $git_range = "-$2 $1";
                } elsif ($commit_expr =~ m/\.\./) {
                        $git_range = "$commit_expr";
                } else {
@@ -821,7 +818,8 @@ if ($git) {
                }
                my $lines = `git log --no-color --no-merges --pretty=format:'%H %s' $git_range`;
                foreach my $line (split(/\n/, $lines)) {
-                       $line =~ /(^\w+) (.*)/;
+                       $line =~ /^([0-9a-fA-F]{40,40}) (.*)$/;
+                       next if (!defined($1) || !defined($2));
                        my $sha1 = $1;
                        my $subject = $2;
                        unshift(@commits, $sha1);