Merge pull request #5813 from curry684/issue-5808

Fix crash when listing root package without versions

src/Composer/Command/ShowCommand.php

@@ -178,7 +178,7 @@ EOT
                 if ($input->getOption('latest')) {
                     $latestPackage = $this->findLatestPackage($package, $composer, $phpVersion);
                 }
-                $this->printMeta($package, $versions, $installedRepo, $latestPackage);
+                $this->printMeta($package, $versions, $installedRepo, $latestPackage ?: null);
                 $this->printLinks($package, 'requires');
                 $this->printLinks($package, 'devRequires', 'requires (dev)');
                 if ($package->getSuggests()) {