symfony
diff --git a/‎src/Symfony/Component/Process/Process.php
Lines changed: 8 additions & 7 deletions b/‎src/Symfony/Component/Process/Process.php
Lines changed: 8 additions & 7 deletions
diff --git a/‎src/Symfony/Component/Process/Tests/ProcessTest.php
Lines changed: 9 additions & 1 deletion b/‎src/Symfony/Component/Process/Tests/ProcessTest.php
Lines changed: 9 additions & 1 deletion
@@ -450,27 +450,28 @@ public function waitUntil(callable $callback): bool
         }
         $callback = $this->buildCallback($callback);
 
-        $wait = true;
-        do {
+        $ready = false;
+        while (true) {
             $this->checkTimeout();
             $running = '\\' === \DIRECTORY_SEPARATOR ? $this->isRunning() : $this->processPipes->areOpen();
             $output = $this->processPipes->readAndWrite($running, '\\' !== \DIRECTORY_SEPARATOR || !$running);
 
             foreach ($output as $type => $data) {
                 if (3 !== $type) {
-                    $wait = !$callback(self::STDOUT === $type ? self::OUT : self::ERR, $data);
+                    $ready = $ready || $callback(self::STDOUT === $type ? self::OUT : self::ERR, $data);
                 } elseif (!isset($this->fallbackStatus['signaled'])) {
                     $this->fallbackStatus['exitcode'] = (int) $data;
                 }
             }
-            if ($wait && !$this->isRunning()) {
+            if ($ready) {
+                return true;
+            }
+            if (!$running) {
                 return false;
             }
 
             usleep(1000);
-        } while ($wait);
-
-        return true;
+        }
     }
 
     /**
 
@@ -141,7 +141,7 @@ public function testWaitUntilSpecificOutput()
         $start = microtime(true);
 
         $completeOutput = '';
-        $p->waitUntil(function ($type, $output) use (&$completeOutput) {
+        $result = $p->waitUntil(function ($type, $output) use (&$completeOutput) {
             $completeOutput .= $output;
             if (false !== strpos($output, 'One more')) {
                 return true;
@@ -150,6 +150,7 @@ public function testWaitUntilSpecificOutput()
             return false;
         });
         $p->stop();
+        $this->assertTrue($result);
 
         if ('\\' === \DIRECTORY_SEPARATOR) {
             // Windows is slower
@@ -160,6 +161,13 @@ public function testWaitUntilSpecificOutput()
         $this->assertEquals("First iteration output\nSecond iteration output\nOne more iteration output\n", $completeOutput);
     }
 
+    public function testWaitUntilCanReturnFalse()
+    {
+        $p = $this->getProcess('echo foo');
+        $p->start();
+        $this->assertFalse($p->waitUntil(function () { return false; }));
+    }
+
     public function testAllOutputIsActuallyReadOnTermination()
     {
         // this code will result in a maximum of 2 reads of 8192 bytes by calling