Consider replaces when checking package dependents

src/Composer/Repository/BaseRepository.php

@@ -67,6 +67,24 @@ abstract class BaseRepository implements RepositoryInterface
             // Replacements are considered valid reasons for a package to be installed during forward resolution
             if (!$invert) {
                 $links += $package->getReplaces();
+
+                foreach ($package->getReplaces() as $link) {
+                    foreach ($needles as $needle) {
+                        if ($link->getSource() === $needle) {
+                            if ($constraint === null || ($link->getConstraint()->matches($constraint) === !$invert)) {
+                                // already displayed this node's dependencies, cutting short
+                                if (in_array($link->getTarget(), $packagesInTree)) {
+                                    $results[$link->getTarget()] = array($package, $link, false);
+                                    continue;
+                                }
+                                $packagesInTree[] = $link->getTarget();
+                                $dependents = $recurse ? $this->getDependents($link->getTarget(), null, false, true, $packagesInTree) : array();
+                                $results[] = array($package, $link, $dependents);
+                                $needles[] = $link->getTarget();
+                            }
+                        }
+                    }
+                }
             }
 
             // Require-dev is only relevant for the root package
@@ -81,12 +99,12 @@ abstract class BaseRepository implements RepositoryInterface
                         if ($constraint === null || ($link->getConstraint()->matches($constraint) === !$invert)) {
                             // already displayed this node's dependencies, cutting short
                             if (in_array($link->getSource(), $packagesInTree)) {
-                                $results[$link->getSource()] = array($package, $link, false);
+                                $results[] = array($package, $link, false);
                                 continue;
                             }
                             $packagesInTree[] = $link->getSource();
                             $dependents = $recurse ? $this->getDependents($link->getSource(), null, false, true, $packagesInTree) : array();
-                            $results[$link->getSource()] = array($package, $link, $dependents);
+                            $results[] = array($package, $link, $dependents);
                         }
                     }
                 }