[Process] Fix dealing with broken stdin pipes

Author: nicolas-grekas

Pipes/AbstractPipes.php

@@ -135,9 +135,11 @@ protected function write(): ?array
 
         foreach ($w as $stdin) {
             if (isset($this->inputBuffer[0])) {
-                $written = fwrite($stdin, $this->inputBuffer);
+                if (false === $written = @fwrite($stdin, $this->inputBuffer)) {
+                    return $this->closeBrokenInputPipe();
+                }
                 $this->inputBuffer = substr($this->inputBuffer, $written);
-                if (isset($this->inputBuffer[0])) {
+                if (isset($this->inputBuffer[0]) && isset($this->pipes[0])) {
                     return [$this->pipes[0]];
                 }
             }
@@ -148,12 +150,14 @@ protected function write(): ?array
                     if (!isset($data[0])) {
                         break;
                     }
-                    $written = fwrite($stdin, $data);
+                    if (false === $written = @fwrite($stdin, $data)) {
+                        return $this->closeBrokenInputPipe();
+                    }
                     $data = substr($data, $written);
                     if (isset($data[0])) {
                         $this->inputBuffer = $data;
 
-                        return [$this->pipes[0]];
+                        return isset($this->pipes[0]) ? [$this->pipes[0]] : null;
                     }
                 }
                 if (feof($input)) {
@@ -178,6 +182,18 @@ protected function write(): ?array
         return null;
     }
 
+    private function closeBrokenInputPipe(): void
+    {
+        $this->lastError = error_get_last()['message'] ?? null;
+        if (\is_resource($this->pipes[0] ?? null)) {
+            fclose($this->pipes[0]);
+        }
+        unset($this->pipes[0]);
+
+        $this->input = null;
+        $this->inputBuffer = '';
+    }
+
     /**
      * @internal
      */

Tests/ProcessTest.php

@@ -672,6 +672,24 @@ public function testStop()
         $this->assertFalse($process->isRunning());
     }
 
+    public function testStopDoesNotThrowAfterBrokenPipe()
+    {
+        if ('\\' === \DIRECTORY_SEPARATOR) {
+            $this->markTestSkipped('Broken pipe notices are specific to Unix-like platforms.');
+        }
+
+        $process = $this->getProcess([self::$phpBin, '-r', 'exit(0);'], null, null, str_repeat('*', PipesInterface::CHUNK_SIZE * 32));
+
+        $process->run();
+        $this->assertSame(0, $process->getExitCode());
+
+        $process->stop(0);
+
+        // __destruct() should not trigger a broken pipe notice
+        self::$process = $process = null;
+        gc_collect_cycles();
+    }
+
     public function testIsSuccessful()
     {
         $process = $this->getProcess('echo foo');