From 935c8b5875fadd80bb2c7c2fcf800bd0192aa3d2 Mon Sep 17 00:00:00 2001
From: Greg Sherwood <gsherwood@squiz.net>
Date: Fri, 24 Nov 2017 09:17:20 +1100
Subject: [PATCH] Fixed bug #1758 : PHPCS gets stuck creating file list when
 processing circular symlinks

---
 package.xml            |  1 +
 src/Filters/Filter.php | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/package.xml b/package.xml
index 1a83948a43..a665409f1e 100644
--- a/package.xml
+++ b/package.xml
@@ -101,6 +101,7 @@ http://pear.php.net/dtd/package-2.0.xsd">
   - Fixed bug #1731 : Directory exclusions do not work as expected when a single file name is passed to phpcs
   - Fixed bug #1746 : Very large reports can sometimes become garbled when using the parallel option
   - Fixed bug #1757 : Unknown type hint "object" in Squiz.Commenting.FunctionComment
+  - Fixed bug #1758 : PHPCS gets stuck creating file list when processing circular symlinks
  </notes>
  <contents>
   <dir name="/">
diff --git a/src/Filters/Filter.php b/src/Filters/Filter.php
index c053c06b58..b7a6c2aa29 100644
--- a/src/Filters/Filter.php
+++ b/src/Filters/Filter.php
@@ -50,6 +50,15 @@ class Filter extends \RecursiveFilterIterator
      */
     protected $ignoreFilePatterns = null;
 
+    /**
+     * A list of file paths we've already accepted.
+     *
+     * Used to ensure we aren't following circular symlinks.
+     *
+     * @var array
+     */
+    protected $acceptedPaths = [];
+
 
     /**
      * Constructs a filter.
@@ -82,7 +91,18 @@ public function __construct($iterator, $basedir, Config $config, Ruleset $rulese
     public function accept()
     {
         $filePath = $this->current();
+        $realPath = Util\Common::realpath($filePath);
 
+        if ($realPath !== false) {
+            // It's a real path somewhere, so record it
+            // to check for circular symlinks.
+            if (isset($this->acceptedPaths[$realPath]) === true) {
+                // We've been here before.
+                return false;
+            }
+        }
+
+        $filePath = $this->current();
         if (is_dir($filePath) === true) {
             if ($this->config->local === true) {
                 return false;
@@ -95,6 +115,7 @@ public function accept()
             return false;
         }
 
+        $this->acceptedPaths[$realPath] = true;
         return true;
 
     }//end accept()
@@ -120,6 +141,7 @@ public function getChildren()
         // Set the ignore patterns so we don't have to generate them again.
         $children->ignoreDirPatterns  = $this->ignoreDirPatterns;
         $children->ignoreFilePatterns = $this->ignoreFilePatterns;
+        $children->acceptedPaths      = $this->acceptedPaths;
         return $children;
 
     }//end getChildren()