scripts: validate the first Comments-URI entry

.github/workflows/github-action-checks.yml

@@ -11,6 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
+      - run: prove scripts/t/*.t
       - run: scripts/buildtable.pl >/tmp/table.mediawiki || exit 1
   Diff-Checks:
     name: "Diff Checks (fails until number assignment)"

scripts/buildtable.pl

@@ -197,7 +197,7 @@
 				die "Unacceptable license $val in $fn" unless exists $AcceptableLicenses{$val} or ($val eq 'PD' and exists $GrandfatheredPD{$bipnum}) or ($val eq 'CC-BY-SA-4.0' and exists $GrandfatheredCCBySA{$bipnum});
 			}
 		} elsif ($field eq 'Comments-URI') {
-			if ($found{'Comments-URI'}) {
+			if (not $found{'Comments-URI'}) {
 				my $first_comments_uri = sprintf('https://github.com/bitcoin/bips/wiki/Comments:BIP-%04d', $bipnum);
 				die "First Comments-URI must be exactly \"$first_comments_uri\" in $fn" unless $val eq $first_comments_uri;
 			}

scripts/t/buildtable-comments-uri.t

@@ -0,0 +1,72 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+use File::Spec;
+use File::Temp qw(tempdir);
+use FindBin;
+use Test::More;
+
+my $buildtable = File::Spec->catfile($FindBin::Bin, '..', 'buildtable.pl');
+
+sub run_buildtable {
+	my (@comments_uris) = @_;
+	my $dir = tempdir(CLEANUP => 1);
+	my $bip = File::Spec->catfile($dir, 'bip-0001.mediawiki');
+	my $stdout = File::Spec->catfile($dir, 'stdout');
+	my $stderr = File::Spec->catfile($dir, 'stderr');
+
+	open my $BIP, '>', $bip or die "Could not create $bip: $!";
+	print {$BIP} "<pre>\n";
+	print {$BIP} "  BIP: 1\n";
+	print {$BIP} "  Title: Test BIP\n";
+	print {$BIP} "  Authors: Test Author <test\@example.com>\n";
+	print {$BIP} "  Comments-URI: $comments_uris[0]\n";
+	for my $uri (@comments_uris[1 .. $#comments_uris]) {
+		print {$BIP} ' ' x (4 + length('Comments-URI')), "$uri\n";
+	}
+	print {$BIP} "  Status: Draft\n";
+	print {$BIP} "  Type: Process\n";
+	print {$BIP} "  Assigned: 2026-08-03\n";
+	print {$BIP} "</pre>\n";
+	close $BIP or die "Could not close $bip: $!";
+
+	my $pid = fork // die "Could not fork: $!";
+	if ($pid == 0) {
+		chdir $dir or die "Could not chdir to $dir: $!";
+		open STDOUT, '>', $stdout or die "Could not open $stdout: $!";
+		open STDERR, '>', $stderr or die "Could not open $stderr: $!";
+		exec $^X, $buildtable;
+		die "Could not execute $buildtable: $!";
+	}
+	waitpid $pid, 0;
+	my $exit_code = $? >> 8;
+
+	open my $ERRORS, '<', $stderr or die "Could not open $stderr: $!";
+	my $errors = do { local $/; <$ERRORS> };
+	close $ERRORS;
+
+	return ($exit_code, $errors);
+}
+
+my $wiki_uri = 'https://github.com/bitcoin/bips/wiki/Comments:BIP-0001';
+
+{
+	my ($exit_code, $errors) = run_buildtable($wiki_uri);
+	is($exit_code, 0, 'accepts the standard Comments wiki URI');
+	is($errors, '', 'does not report an error for the standard Comments wiki URI');
+}
+
+{
+	my ($exit_code, $errors) = run_buildtable('https://example.com/wrong');
+	isnt($exit_code, 0, 'rejects a nonstandard first Comments-URI');
+	like($errors, qr/First Comments-URI must be exactly/, 'reports the invalid first Comments-URI');
+}
+
+{
+	my ($exit_code, $errors) = run_buildtable($wiki_uri, 'https://example.com/discussion');
+	is($exit_code, 0, 'accepts an additional external discussion URI');
+	is($errors, '', 'does not report an error for an additional discussion URI');
+}
+
+done_testing();