start install-extension

gistfile1.php

diff --git a/src/Composer/Command/InstallCommand.php b/src/Composer/Command/InstallCommand.php
index e548b8d..9803878 100644
--- a/src/Composer/Command/InstallCommand.php
+++ b/src/Composer/Command/InstallCommand.php
@@ -47,6 +47,7 @@ class InstallCommand extends Command
                 new InputOption('verbose', 'v|vv|vvv', InputOption::VALUE_NONE, 'Shows more details including new commits pulled in when updating packages.'),
                 new InputOption('optimize-autoloader', 'o', InputOption::VALUE_NONE, 'Optimize autoloader during autoloader dump'),
                 new InputOption('ignore-platform-reqs', null, InputOption::VALUE_NONE, 'Ignore platform requirements (php & ext- packages).'),
+				new InputOption('install-extensions', null, InputOption::VALUE_NONE, 'install PHP extensions'),
                 new InputArgument('packages', InputArgument::IS_ARRAY | InputArgument::OPTIONAL, 'Should not be provided, use composer require instead to add a given package to composer.json.'),
             ))
             ->setHelp(<<<EOT
@@ -122,6 +123,7 @@ EOT
             ->setRunScripts(!$input->getOption('no-scripts'))
             ->setOptimizeAutoloader($optimize)
             ->setIgnorePlatformRequirements($input->getOption('ignore-platform-reqs'))
+			->setInstallExtensions($input->getOption('install-extensions'));
         ;
 
         if ($input->getOption('no-plugins')) {
diff --git a/src/Composer/DependencyResolver/RuleSetGenerator.php b/src/Composer/DependencyResolver/RuleSetGenerator.php
index 8ea24e7..4154476 100644
--- a/src/Composer/DependencyResolver/RuleSetGenerator.php
+++ b/src/Composer/DependencyResolver/RuleSetGenerator.php
@@ -179,7 +179,7 @@ class RuleSetGenerator
         }
     }
 
-    protected function addRulesForPackage(PackageInterface $package, $ignorePlatformReqs)
+    protected function addRulesForPackage(PackageInterface $package, $ignorePlatformReqs, $installExtensions = false)
     {
         $workQueue = new \SplQueue;
         $workQueue->enqueue($package);
@@ -190,6 +190,10 @@ class RuleSetGenerator
                 continue;
             }
 
+			if (!$installExtensions && $package->getType() == 'extension') {
+				continue;
+			}
+
             $this->addedMap[$package->id] = true;
 
             foreach ($package->getRequires() as $link) {
@@ -311,7 +315,7 @@ class RuleSetGenerator
         }
     }
 
-    public function getRulesFor($jobs, $installedMap, $ignorePlatformReqs = false)
+    public function getRulesFor($jobs, $installedMap, $ignorePlatformReqs = false, $installExtensions = false)
     {
         $this->jobs = $jobs;
         $this->rules = new RuleSet;
@@ -327,7 +331,7 @@ class RuleSetGenerator
 
         $this->addedMap = array();
         foreach ($this->installedMap as $package) {
-            $this->addRulesForPackage($package, $ignorePlatformReqs);
+            $this->addRulesForPackage($package, $ignorePlatformReqs, $installExtensions);
         }
 
         $this->addRulesForJobs($ignorePlatformReqs);
diff --git a/src/Composer/DependencyResolver/Solver.php b/src/Composer/DependencyResolver/Solver.php
index 77a945f..218fc8e 100644
--- a/src/Composer/DependencyResolver/Solver.php
+++ b/src/Composer/DependencyResolver/Solver.php
@@ -130,7 +130,7 @@ class Solver
         }
     }
 
-    protected function checkForRootRequireProblems($ignorePlatformReqs)
+    protected function checkForRootRequireProblems($ignorePlatformReqs, $installExtensions)
     {
         foreach ($this->jobs as $job) {
             switch ($job['cmd']) {
@@ -164,13 +164,13 @@ class Solver
         }
     }
 
-    public function solve(Request $request, $ignorePlatformReqs = false)
+    public function solve(Request $request, $ignorePlatformReqs = false, $installExtensions = false)
     {
         $this->jobs = $request->getJobs();
 
         $this->setupInstalledMap();
         $this->rules = $this->ruleSetGenerator->getRulesFor($this->jobs, $this->installedMap, $ignorePlatformReqs);
-        $this->checkForRootRequireProblems($ignorePlatformReqs);
+        $this->checkForRootRequireProblems($ignorePlatformReqs, $installExtensions);
         $this->decisions = new Decisions($this->pool);
         $this->watchGraph = new RuleWatchGraph;
 
diff --git a/src/Composer/Installer.php b/src/Composer/Installer.php
index 89ecd06..92f9f0a 100644
--- a/src/Composer/Installer.php
+++ b/src/Composer/Installer.php
@@ -108,6 +108,7 @@ class Installer
     protected $dumpAutoloader = true;
     protected $runScripts = true;
     protected $ignorePlatformReqs = false;
+    protected $installExtensions = false;
     protected $preferStable = false;
     protected $preferLowest = false;
     /**
@@ -500,7 +501,7 @@ class Installer
         $this->eventDispatcher->dispatchInstallerEvent(InstallerEvents::PRE_DEPENDENCIES_SOLVING, $this->devMode, $policy, $pool, $installedRepo, $request);
         $solver = new Solver($policy, $pool, $installedRepo);
         try {
-            $operations = $solver->solve($request, $this->ignorePlatformReqs);
+            $operations = $solver->solve($request, $this->ignorePlatformReqs, $this->installExtensions);
             $this->eventDispatcher->dispatchInstallerEvent(InstallerEvents::POST_DEPENDENCIES_SOLVING, $this->devMode, $policy, $pool, $installedRepo, $request, $operations);
         } catch (SolverProblemsException $e) {
             $this->io->writeError('<error>Your requirements could not be resolved to an installable set of packages.</error>');
@@ -1254,6 +1255,19 @@ class Installer
     }
 
     /**
+     * set install Extensions flag
+     *
+     * @param  boolean   $installExtensions
+     * @return Installer
+     */
+    public function setInstallExtensions($installExtensions = false)
+    {
+        $this->installExtensions = (boolean) $installExtensions;
+
+        return $this;
+    }
+
+    /**
      * restrict the update operation to a few packages, all other packages
      * that are already installed will be kept at their current version
      *
diff --git a/src/Composer/Installer/ExtensionInstaller.php b/src/Composer/Installer/ExtensionInstaller.php
index 60fad8e..150da06 100644
--- a/src/Composer/Installer/ExtensionInstaller.php
+++ b/src/Composer/Installer/ExtensionInstaller.php
@@ -71,7 +71,7 @@ class ExtensionInstaller implements InstallerInterface
      */
     public function install(InstalledRepositoryInterface $repo, PackageInterface $package)
     {
-
+        debug_print_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
         $this->io->write("Pickle: fetching " . $package->getName());
 
         $distUrl = $package->getDistURL();
diff --git a/src/Composer/Installer/InstallationManager.php b/src/Composer/Installer/InstallationManager.php
index a43acbb..534812d 100644
--- a/src/Composer/Installer/InstallationManager.php
+++ b/src/Composer/Installer/InstallationManager.php
@@ -148,6 +148,11 @@ class InstallationManager
     public function install(RepositoryInterface $repo, InstallOperation $operation)
     {
         $package = $operation->getPackage();
+		$type = $package->getType();
+		if ($type == 'extension') {
+			print "run composer install --install-extension\n";
+			return;
+		}
         $installer = $this->getInstaller($package->getType());
         $installer->install($repo, $package);
         $this->markForNotification($package);
diff --git a/src/bootstrap.php b/src/bootstrap.php
index 338b3cc..7391f8e 100644
--- a/src/bootstrap.php
+++ b/src/bootstrap.php
@@ -21,5 +21,4 @@ if ((!$loader = includeIfExists(__DIR__.'/../vendor/autoload.php')) && (!$loader
         'php composer.phar install'.PHP_EOL;
     exit(1);
 }
-
 return $loader;