From 4a945da55b406c88c33770cde316675efc3c2862 Mon Sep 17 00:00:00 2001
From: Nils Adermann <naderman@naderman.de>
Date: Mon, 1 Dec 2014 19:21:33 +0100
Subject: [PATCH] Avoid generating duplicate conflict rules

For each version of each package we create a conflict rule with each
other version. These are then added to the rule set and skipped if
duplicate so instead we can just generate them only once to begin with
and avoid unnecessary memory allocation and duplication lookups.
---
 src/Composer/DependencyResolver/RuleSetGenerator.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Composer/DependencyResolver/RuleSetGenerator.php b/src/Composer/DependencyResolver/RuleSetGenerator.php
index 8ea24e742..30e3a0964 100644
--- a/src/Composer/DependencyResolver/RuleSetGenerator.php
+++ b/src/Composer/DependencyResolver/RuleSetGenerator.php
@@ -241,7 +241,7 @@ class RuleSetGenerator
 
                 if (($package instanceof AliasPackage) && $package->getAliasOf() === $provider) {
                     $this->addRule(RuleSet::TYPE_PACKAGE, $rule = $this->createRequireRule($package, array($provider), Rule::RULE_PACKAGE_ALIAS, $package));
-                } elseif (!$this->obsoleteImpossibleForAlias($package, $provider)) {
+                } elseif (!$this->obsoleteImpossibleForAlias($package, $provider) && $package->id <= $provider->id) {
                     $reason = ($package->getName() == $provider->getName()) ? Rule::RULE_PACKAGE_SAME_NAME : Rule::RULE_PACKAGE_IMPLICIT_OBSOLETES;
                     $this->addRule(RuleSet::TYPE_PACKAGE, $rule = $this->createConflictRule($package, $provider, $reason, $package));
                 }