Fixed amphp#28 (Pool::init() possibly returning null)

Author: bwoebi

lib/Connection.php

@@ -46,8 +46,6 @@ public function __construct($config, $sslOptions = null) {
 		$this->processor = new Processor($ready, $busy, $restore);
 		$this->processor->config = $config;
 	}
-	
-	
 
 	public static function parseConnStr($connStr, $sslOptions = null) {
 		$db = null;

lib/ConnectionPool.php

@@ -7,7 +7,7 @@ class ConnectionPool {
 	private $connectionMap = [];
 	private $ready = [];
 	private $readyMap = [];
-	private $connectionPromise;
+	private $connectionDeferred;
 	private $virtualConnection;
 	private $config;
 	private $limit;
@@ -38,7 +38,17 @@ public function __construct($config, $limit) {
 	}
 
 	public function getConnectionPromise() {
-		return $this->connectionPromise;
+		if (isset($this->connectionDeferred)) {
+			return $this->connectionDeferred->promise();
+		}
+		if ($this->connections) {
+			foreach ($this->connections as $conn) {
+				if ($conn->isReady()) {
+					return new \Amp\Success;
+				}
+			}
+		}
+		return ($this->connectionDeferred = new \Amp\Deferred)->promise();
 	}
 
 	public function addConnection() {
@@ -50,16 +60,29 @@ public function addConnection() {
 			$this->connections[] = $conn = new Connection($this->config);
 			end($this->connections);
 			$this->connectionMap[spl_object_hash($conn)] = key($this->connections);
-			$this->connectionPromise = $conn->connect();
-			$this->connectionPromise->when(function ($error) use ($conn) {
+			$conn->connect()->when(function ($error) use ($conn) {
+				if (!$error && !$conn->isReady()) {
+					$error = new InitializationException("Connection closed before being established");
+				}
 				if ($error) {
 					$this->unmapConnection(spl_object_hash($conn));
 					if (empty($this->connections)) {
 						$this->virtualConnection->fail($error);
+						$deferred = $this->connectionDeferred;
+						if ($deferred) {
+							$this->connectionDeferred = null;
+							$deferred->fail($error);
+						}
 					}
 					return;
 				}
 
+				if (isset($this->connectionDeferred)) {
+					$deferred = $this->connectionDeferred;
+					$this->connectionDeferred = null;
+					$deferred->succeed();
+				}
+
 				if ($this->config->charset != "utf8mb4" || ($this->config->collate != "" && $this->config->collate != "utf8mb4_general_ci")) {
 					$conn->setCharset($this->config->charset, $this->config->collate);
 				}
@@ -86,9 +109,6 @@ public function setCharset($charset, $collate = "") {
 
 	public function useExceptions($set) {
 		$this->config->exceptions = $set;
-		foreach ($this->connections as $conn) {
-			$conn->useExceptions($set);
-		}
 	}
 
 	private function ready($hash) {