Bug#986400: lintian: false positive about permissions for read-only GNAT .ali files

[Nicolas Boulenguez <nicolas@debian.org>]

Package: lintian
Severity: normal
Tags: patch

Hello.
Lintian once was behaving as expected:
 /usr/lib/foo/bar.ali 444 -> OK
 /usr/lib/foo/baz.ali 644 -> bad-permissions-for-ali-file
but commit 3f71a11f has introduced a false positive:
 /usr/lib/foo/bar.ali 444 -> non-standard-file-perm
 /usr/lib/foo/baz.ali 644 -> bad-permissions-for-ali-file
The attached patch should restore the correct behaviour.

>From 2ba6c68d7f4a6ee83a97270fe34fd69c59ff95c3 Mon Sep 17 00:00:00 2001
From: Nicolas Boulenguez <nicolas.boulenguez@free.fr>
Date: Sun, 4 Apr 2021 14:09:12 +0200
Subject: Remove hint about permissions for read-only GNAT .ali files

Lintian once was behaving as expected:
 /usr/lib/foo/bar.ali 444 -> OK
 /usr/lib/foo/baz.ali 644 -> bad-permissions-for-ali-file
but commit 3f71a11f has introduced a false positive:
 /usr/lib/foo/bar.ali 444 -> non-standard-file-perm
 /usr/lib/foo/baz.ali 644 -> bad-permissions-for-ali-file

diff --git a/lib/Lintian/Check/Files/Permissions.pm b/lib/Lintian/Check/Files/Permissions.pm
index 45bf94476..624626a12 100644
--- a/lib/Lintian/Check/Files/Permissions.pm
+++ b/lib/Lintian/Check/Files/Permissions.pm
@@ -172,11 +172,9 @@ sub visit_installed_files {
               && $file->name =~ m{^ var/ (?:lib/)? games/ \S+ }msx;
 
             # GNAT compiler wants read-only Ada library information.
-            if (   $file->name =~ m{^ usr/lib/ .* [.]ali $}msx
-                && $file->operm != $WORLD_READABLE) {
-
-                $self->hint('bad-permissions-for-ali-file', $file->name);
-
+            if ($file->name =~ m{^ usr/lib/ .* [.]ali $}msx) {
+                $self->hint('bad-permissions-for-ali-file', $file->name)
+                    unless $file->operm == $WORLD_READABLE;
                 return;
             }