From 7a33b9273e2e51ec2654fc76035bce18abefcbb7 Mon Sep 17 00:00:00 2001
From: tux-rampage <tux-rampage@users.noreply.github.com>
Date: Wed, 6 Sep 2017 21:28:45 +0200
Subject: [PATCH] Refactor webroot detection in resource locator

The current implementation breaks installations with symlinks to
directories inside the webroot (i.E. apps).

With this change both variants, directory and symlinks, will be detected
correctly.

Fixes: #6028
Signed-off-by: Axel Helmert <axel.helmert@luka.de>
---
 lib/private/Template/CSSResourceLocator.php | 44 +++--------
 lib/private/Template/ResourceLocator.php    | 88 +++++++++++++--------
 2 files changed, 68 insertions(+), 64 deletions(-)

diff --git a/lib/private/Template/CSSResourceLocator.php b/lib/private/Template/CSSResourceLocator.php
index 32dabb48c0d8c..1b4050e4ae04a 100644
--- a/lib/private/Template/CSSResourceLocator.php
+++ b/lib/private/Template/CSSResourceLocator.php
@@ -117,38 +117,18 @@ public function append($root, $file, $webRoot = null, $throw = true, $scss = fal
 			parent::append($root, $file, $webRoot, $throw);
 		} else {
 			if (!$webRoot) {
-				$tmpRoot = realpath($root);
-				/*
-				 * traverse the potential web roots upwards in the path
-				 *
-				 * example:
-				 *   - root: /srv/www/apps/myapp
-				 *   - available mappings: ['/srv/www']
-				 *
-				 * First we check if a mapping for /srv/www/apps/myapp is available,
-				 * then /srv/www/apps, /srv/www/apps, /srv/www, ... until we find a
-				 * valid web root
-				 */
-				do {
-					if (isset($this->mapping[$tmpRoot])) {
-						$webRoot = $this->mapping[$tmpRoot];
-						break;
-					}
-
-					if ($tmpRoot === '/') {
-						$webRoot = '';
-						$this->logger->error('ResourceLocator can not find a web root (root: {root}, file: {file}, webRoot: {webRoot}, throw: {throw})', [
-							'app' => 'lib',
-							'root' => $root,
-							'file' => $file,
-							'webRoot' => $webRoot,
-							'throw' => $throw ? 'true' : 'false'
-						]);
-						break;
-					}
-					$tmpRoot = dirname($tmpRoot);
-				} while(true);
-
+				$webRoot = $this->findWebRoot($root);
+
+				if (!$webRoot) {
+					$webRoot = '';
+					$this->logger->error('ResourceLocator can not find a web root (root: {root}, file: {file}, webRoot: {webRoot}, throw: {throw})', [
+						'app' => 'lib',
+						'root' => $root,
+						'file' => $file,
+						'webRoot' => $webRoot,
+						'throw' => $throw ? 'true' : 'false'
+					]);
+				}
 			}
 
 			if ($throw && $tmpRoot === '/') {
diff --git a/lib/private/Template/ResourceLocator.php b/lib/private/Template/ResourceLocator.php
index f721906e12ba3..2127161f28c20 100755
--- a/lib/private/Template/ResourceLocator.php
+++ b/lib/private/Template/ResourceLocator.php
@@ -106,6 +106,50 @@ protected function appendIfExist($root, $file, $webRoot = null) {
 		return false;
 	}
 
+	/**
+	 * Attempt to find the webRoot
+	 *
+	 * traverse the potential web roots upwards in the path
+	 *
+	 * example:
+	 *   - root: /srv/www/apps/myapp
+	 *   - available mappings: ['/srv/www']
+	 *
+	 * First we check if a mapping for /srv/www/apps/myapp is available,
+	 * then /srv/www/apps, /srv/www/apps, /srv/www, ... until we find a
+	 * valid web root
+	 *
+	 * @param string $root
+	 * @return string|null The web root or null on failure
+	 */
+	protected function findWebRoot($root) {
+		$webRoot = null;
+		$tmpRoot = $root;
+
+		while ($webRoot === null) {
+			if (isset($this->mapping[$tmpRoot])) {
+				$webRoot = $this->mapping[$tmpRoot];
+				break;
+			}
+
+			if ($tmpRoot === '/') {
+				break;
+			}
+
+			$tmpRoot = dirname($tmpRoot);
+		}
+
+		if (!$webRoot) {
+			$realpath = realpath($root);
+
+			if ($realpath && ($realpath !== $root)) {
+				return $this->findWebRoot($realpath);
+			}
+		}
+
+		return $webRoot;
+	}
+
 	/**
 	 * append the $file resource at $root
 	 *
@@ -125,38 +169,18 @@ protected function append($root, $file, $webRoot = null, $throw = true) {
 		}
 
 		if (!$webRoot) {
-			$tmpRoot = realpath($root);
-			/*
-			 * traverse the potential web roots upwards in the path
-			 *
-			 * example:
-			 *   - root: /srv/www/apps/myapp
-			 *   - available mappings: ['/srv/www']
-			 *
-			 * First we check if a mapping for /srv/www/apps/myapp is available,
-			 * then /srv/www/apps, /srv/www/apps, /srv/www, ... until we find a
-			 * valid web root
-			 */
-			do {
-				if (isset($this->mapping[$tmpRoot])) {
-					$webRoot = $this->mapping[$tmpRoot];
-					break;
-				}
-
-				if ($tmpRoot === '/') {
-					$webRoot = '';
-					$this->logger->error('ResourceLocator can not find a web root (root: {root}, file: {file}, webRoot: {webRoot}, throw: {throw})', [
-						'app' => 'lib',
-						'root' => $root,
-						'file' => $file,
-						'webRoot' => $webRoot,
-						'throw' => $throw ? 'true' : 'false'
-					]);
-					break;
-				}
-				$tmpRoot = dirname($tmpRoot);
-			} while(true);
-
+			$webRoot = $this->findWebRoot($root);
+
+			if (!$webRoot) {
+				$webRoot = '';
+				$this->logger->error('ResourceLocator can not find a web root (root: {root}, file: {file}, webRoot: {webRoot}, throw: {throw})', [
+					'app' => 'lib',
+					'root' => $root,
+					'file' => $file,
+					'webRoot' => $webRoot,
+					'throw' => $throw ? 'true' : 'false'
+				]);
+			}
 		}
 		$this->resources[] = array($root, $webRoot, $file);