From 5ccce215a17e7ed546143bb1094608ad6b8e9332 Mon Sep 17 00:00:00 2001
From: Alexander Ebert <ebert@woltlab.com>
Date: Thu, 6 Dec 2012 18:10:31 +0100
Subject: [PATCH] Disallowing uninstallation of required packages

Fixes #
---
 .../{packageView.tpl => package.tpl}          |  4 +-
 .../acp/templates/packageListDetailed.tpl     |  2 +-
 .../files/lib/data/package/Package.class.php  | 80 +++++++++++++++++--
 3 files changed, 76 insertions(+), 10 deletions(-)
 rename wcfsetup/install/files/acp/templates/{packageView.tpl => package.tpl} (97%)

diff --git a/wcfsetup/install/files/acp/templates/packageView.tpl b/wcfsetup/install/files/acp/templates/package.tpl
similarity index 97%
rename from wcfsetup/install/files/acp/templates/packageView.tpl
rename to wcfsetup/install/files/acp/templates/package.tpl
index 677da369a2..42d731a5dc 100644
--- a/wcfsetup/install/files/acp/templates/packageView.tpl
+++ b/wcfsetup/install/files/acp/templates/package.tpl
@@ -134,7 +134,7 @@
 											{else}
 												<img src="{@$__wcf->getPath()}icon/update.svg" alt="" title="{lang}wcf.acp.package.button.update{/lang}" class="icon16 disabled" />
 											{/if}
-											{if $__wcf->session->getPermission('admin.system.package.canUninstallPackage') && $requiredPackage->package != 'com.woltlab.wcf' && $requiredPackage->packageID != PACKAGE_ID}
+											{if $requiredPackage->canUninstall()}
 												<img src="{@$__wcf->getPath()}icon/delete.svg" alt="" title="{lang}wcf.acp.package.button.uninstall{/lang}" class="icon16 jsTooltip jsUninstallButton" data-objectID="{@$requiredPackage->packageID}" data-confirm-message="{lang package=$requiredPackage}wcf.acp.package.uninstallation.confirm{/lang}" />
 											{else}
 												<img src="{@$__wcf->getPath()}icon/delete.svg" alt="" title="{lang}wcf.acp.package.button.uninstall{/lang}" class="icon16 disabled" />
@@ -194,7 +194,7 @@
 											{else}
 												<img src="{@$__wcf->getPath()}icon/update.svg" alt="" title="{lang}wcf.acp.package.button.update{/lang}" class="icon16 disabled" />
 											{/if}
-											{if $__wcf->session->getPermission('admin.system.package.canUninstallPackage') && $dependentPackage->package != 'com.woltlab.wcf' && $dependentPackage->packageID != PACKAGE_ID}
+											{if $dependentPackage->canUninstall()}
 												<img src="{@$__wcf->getPath()}icon/delete.svg" alt="" title="{lang}wcf.acp.package.button.uninstall{/lang}" class="icon16 jsTooltip jsUninstallButton" data-objectID="{@$dependentPackage->packageID}" data-confirm-message="{lang package=$dependentPackage}wcf.acp.package.uninstallation.confirm{/lang}" />
 											{else}
 												<img src="{@$__wcf->getPath()}icon/delete.svg" alt="" title="{lang}wcf.acp.package.button.uninstall{/lang}" class="icon16 disabled" />
diff --git a/wcfsetup/install/files/acp/templates/packageListDetailed.tpl b/wcfsetup/install/files/acp/templates/packageListDetailed.tpl
index 220836b3c6..cc5ab073ad 100644
--- a/wcfsetup/install/files/acp/templates/packageListDetailed.tpl
+++ b/wcfsetup/install/files/acp/templates/packageListDetailed.tpl
@@ -62,7 +62,7 @@
 							{else}
 								<img src="{@$__wcf->getPath()}icon/update.svg" alt="" title="{lang}wcf.acp.package.button.update{/lang}" class="icon16 disabled" />
 							{/if}
-							{if $__wcf->session->getPermission('admin.system.package.canUninstallPackage') && $package->package != 'com.woltlab.wcf' && $package->packageID != PACKAGE_ID}
+							{if $package->canUninstall()}
 								<img src="{@$__wcf->getPath()}icon/delete.svg" alt="" title="{lang}wcf.acp.package.button.uninstall{/lang}" class="icon16 jsUninstallButton jsTooltip" data-object-id="{@$package->packageID}" data-confirm-message="{lang}wcf.acp.package.uninstallation.confirm{/lang}" />
 							{else}
 								<img src="{@$__wcf->getPath()}icon/delete.svg" alt="" title="{lang}wcf.acp.package.button.uninstall{/lang}" class="icon16 disabled" />
diff --git a/wcfsetup/install/files/lib/data/package/Package.class.php b/wcfsetup/install/files/lib/data/package/Package.class.php
index f970b4853e..44993a77cb 100644
--- a/wcfsetup/install/files/lib/data/package/Package.class.php
+++ b/wcfsetup/install/files/lib/data/package/Package.class.php
@@ -31,6 +31,12 @@ class Package extends DatabaseObject {
 	 */
 	protected static $databaseTableIndexName = 'packageID';
 	
+	/**
+	 * package requirement map
+	 * @var	array<integer>
+	 */
+	protected static $requirementMap = null;
+	
 	/**
 	 * list of packages that this package requires
 	 * @var	array<wcf\data\package\Package>
@@ -61,14 +67,9 @@ class Package extends DatabaseObject {
 	 * @return	boolean
 	 */
 	public function isRequired() {
-		$sql = "SELECT	COUNT(*) AS count
-			FROM	wcf".WCF_N."_package_requirement
-			WHERE	requirement = ?";
-		$statement = WCF::getDB()->prepareStatement($sql);
-		$statement->execute(array($this->packageID));
-		$row = $statement->fetchArray();
+		self::loadRequirementMap();
 		
-		return $row['count'];
+		return (isset(self::$requirementMap[$this->packageID]));
 	}
 	
 	/**
@@ -168,6 +169,71 @@ class Package extends DatabaseObject {
 		return $this->requiredPackages;
 	}
 	
+	/**
+	 * Returns true, if current user can uninstall this package.
+	 * 
+	 * @return	boolean
+	 */
+	public function canUninstall() {
+		if (!WCF::getSession()->getPermission('admin.system.package.canUninstallPackage')) {
+			return false;
+		}
+		
+		// disallow uninstallation of current package or WCF
+		if ($this->package == 'com.woltlab.wcf' || $this->packageID == PACKAGE_ID) {
+			return false;
+		}
+		
+		// check if package is required by current application
+		if (self::isRequiredBy($this->packageID, PACKAGE_ID)) {
+			return false;
+		}
+		
+		return true;
+	}
+	
+	/**
+	 * Returns true, if package $packageID is required by package $targetPackageID.
+	 * 
+	 * @param	integer		$packageID
+	 * @param	integer		$targetPackageID
+	 * @return	boolean
+	 */
+	public static function isRequiredBy($packageID, $targetPackageID) {
+		self::loadRequirementMap();
+		
+		if (isset(self::$requirementMap[$packageID])) {
+			foreach (self::$requirementMap[$packageID] as $requiredBy) {
+				if ($requiredBy == $targetPackageID) {
+					return true;
+				}
+			}
+		}
+		
+		return false;
+	}
+	
+	/**
+	 * Loads package requirement map.
+	 */
+	protected static function loadRequirementMap() {
+		if (self::$requirementMap === null) {
+			$sql = "SELECT	packageID, requirement
+				FROM	wcf".WCF_N."_package_requirement_map";
+			$statement = WCF::getDB()->prepareStatement($sql);
+			$statement->execute();
+			
+			self::$requirementMap = array();
+			while ($row = $statement->fetchArray()) {
+				if (!isset(self::$requirementMap[$row['requirement']])) {
+					self::$requirementMap[$row['requirement']] = array();
+				}
+				
+				self::$requirementMap[$row['requirement']][] = $row['packageID'];
+			}
+		}
+	}
+	
 	/**
 	 * Checks if a package name is valid.
 	 * 
-- 
2.20.1