Simplify code and fix path to composer.json, refs #6001

src/Composer/Command/ShowCommand.php

@@ -168,17 +168,12 @@ EOT
 
                 if (empty($package)) {
                     $options = $input->getOptions();
-                    if (isset($options['working-dir'])) {
-                        $composer_json = $options['working-dir'] . '/composer.json';
-                        if (file_exists($composer_json)) {
-                            $io->writeError('Package ' . $packageFilter . ' not found in ' . $composer_json);
-                            return;
-                        } else {
-                            throw new \InvalidArgumentException('Package ' . $packageFilter . ' not found');
-                        }
-                    } else {
+                    if (!isset($options['working-dir']) || !file_exists('composer.json')) {
                         throw new \InvalidArgumentException('Package ' . $packageFilter . ' not found');
                     }
+
+                    $io->writeError('Package ' . $packageFilter . ' not found in ' . $options['working-dir'] . '/composer.json');
+                    return;
                 }
             } else {
                 $versions = array($package->getPrettyVersion() => $package->getVersion());