Quick proof-of-concept patch for composer/composer#2022

gistfile1.txt

diff --git a/src/Composer/DependencyResolver/RuleSetGenerator.php b/src/Composer/DependencyResolver/RuleSetGenerator.php
index b40ce1a..2255c36 100644
--- a/src/Composer/DependencyResolver/RuleSetGenerator.php
+++ b/src/Composer/DependencyResolver/RuleSetGenerator.php
@@ -12,6 +12,7 @@

 namespace Composer\DependencyResolver;

+use Composer\Package\LinkConstraint\MultiConstraint;
 use Composer\Package\PackageInterface;
 use Composer\Package\AliasPackage;

@@ -165,11 +166,25 @@ class RuleSetGenerator
             }

             foreach ($package->getConflicts() as $link) {
-                $possibleConflicts = $this->pool->whatProvides($link->getTarget(), $link->getConstraint());
+                $constraints = array();
+                $c = $link->getConstraint();
+
+                if ($c instanceof MultiConstraint) {
+                    foreach ($c->getConstraints() as $constraint) {
+                        $constraints[] = $constraint;
+                    }
+                } else {
+                    $constraints[] = $c;
+                }
+
+                foreach ($constraints as $constraint) {
+                    $possibleConflicts = $this->pool->whatProvides($link->getTarget(), $constraint);
+                    foreach ($possibleConflicts as $conflict) {
+                        $this->addRule(RuleSet::TYPE_PACKAGE, $this->createConflictRule($package, $conflict, Rule::RULE_PACKAGE_CONFLICT, $link));
+                    }

-                foreach ($possibleConflicts as $conflict) {
-                    $this->addRule(RuleSet::TYPE_PACKAGE, $this->createConflictRule($package, $conflict, Rule::RULE_PACKAGE_CONFLICT, $link));
                 }
+
             }

             // check obsoletes and implicit obsoletes of a package
diff --git a/src/Composer/Package/LinkConstraint/MultiConstraint.php b/src/Composer/Package/LinkConstraint/MultiConstraint.php
index 836d565..f6c98b6 100644
--- a/src/Composer/Package/LinkConstraint/MultiConstraint.php
+++ b/src/Composer/Package/LinkConstraint/MultiConstraint.php
@@ -66,4 +66,9 @@ class MultiConstraint implements LinkConstraintInterface

         return '['.implode(', ', $constraints).']';
     }
+
+    public function getConstraints()
+    {
+        return $this->constraints;
+    }
 }