fix: Crash on failed socket read

src/Client.php

@@ -912,11 +912,15 @@ protected function _parseCapability($data)
      */
     protected function _sendCmd($cmd)
     {
-        $status = $this->_sock->getStatus();
-        if ($status['eof']) {
-            throw new Exception('Failed to write to socket: connection lost');
+        try {
+            $status = $this->_sock->getStatus();
+            if ($status['eof']) {
+                throw new Exception('Failed to write to socket: connection lost');
+            }
+            $this->_sock->write($cmd . "\r\n");
+        } catch (SocketClientException $e) {
+            throw new Exception($e);
         }
-        $this->_sock->write($cmd . "\r\n");
         $this->_debug("C: $cmd");
     }
 
@@ -937,7 +941,11 @@ protected function _sendStringResponse($str)
      */
     protected function _recvLn()
     {
-        $lastline = rtrim($this->_sock->gets(8192));
+        try {
+            $lastline = rtrim($this->_sock->gets(8192));
+        } catch (SocketClientException $e) {
+            throw new Exception($e);
+        }
         $this->_debug("S: $lastline");
         if ($lastline === '') {
             throw new Exception('Failed to read from socket');
@@ -957,7 +965,11 @@ protected function _recvBytes($length)
         $response = '';
         $response_length = 0;
         while ($response_length < $length) {
-            $response .= $this->_sock->read($length - $response_length);
+            try {
+                $response .= $this->_sock->read($length - $response_length);
+            } catch (SocketClientException $e) {
+                throw new Exception($e);
+            }
             $response_length = strlen($response);
         }
         $this->_debug('S: ' . rtrim($response));

test/Unit/ClientSocketExceptionTest.php

@@ -0,0 +1,162 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Copyright 2026 The Horde Project (http://www.horde.org/)
+ *
+ * See the enclosed file LICENSE for license information (BSD). If you
+ * did not receive this file, see http://www.horde.org/licenses/bsd.
+ */
+
+namespace Horde\ManageSieve\Test\Unit;
+
+use Horde\ManageSieve\Client;
+use Horde\ManageSieve\Exception;
+use Horde\Socket\Client as SocketClient;
+use Horde\Socket\Client\Exception as SocketClientException;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * Client subclass that injects a mock socket to test exception wrapping.
+ */
+class SocketExceptionClient extends Client
+{
+    public function __construct(object $mockSocket)
+    {
+        $this->_params = [
+            'authmethod' => self::AUTH_AUTOMATIC,
+            'bypassauth' => false,
+            'context' => [],
+            'euser' => null,
+            'host' => 'localhost',
+            'logger' => null,
+            'password' => '',
+            'port' => 4190,
+            'secure' => true,
+            'timeout' => 5,
+            'user' => '',
+        ];
+        $this->_state = self::STATE_AUTHENTICATED;
+        $this->_sock = $mockSocket;
+    }
+
+    public function exposeSendCmd(string $cmd): void
+    {
+        $this->_sendCmd($cmd);
+    }
+
+    public function exposeRecvLn(): string
+    {
+        return $this->_recvLn();
+    }
+
+    public function exposeRecvBytes(int $length): string
+    {
+        return $this->_recvBytes($length);
+    }
+}
+
+/**
+ * Mock socket that throws SocketClientException on all I/O operations.
+ */
+class ThrowingSocket
+{
+    public function getStatus(): array
+    {
+        throw new SocketClientException('Connection reset');
+    }
+
+    public function write(string $data): void
+    {
+        throw new SocketClientException('Broken pipe');
+    }
+
+    public function gets(int $size): string
+    {
+        throw new SocketClientException('Error reading data from socket');
+    }
+
+    public function read(int $size): string
+    {
+        throw new SocketClientException('Error reading data from socket');
+    }
+}
+
+/**
+ * Mock socket with a working getStatus() but throwing write().
+ */
+class ThrowingWriteSocket
+{
+    public function getStatus(): array
+    {
+        return ['eof' => false, 'timed_out' => false, 'blocked' => false];
+    }
+
+    public function write(string $data): void
+    {
+        throw new SocketClientException('Broken pipe');
+    }
+}
+
+/**
+ * Tests that SocketClientException from low-level I/O is wrapped in
+ * ManageSieve\Exception, so callers catching ManageSieveException handle
+ * socket errors properly.
+ */
+#[CoversClass(Client::class)]
+class ClientSocketExceptionTest extends TestCase
+{
+    public function testRecvLnWrapsSocketException(): void
+    {
+        $client = new SocketExceptionClient(new ThrowingSocket());
+
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Error reading data from socket');
+        $client->exposeRecvLn();
+    }
+
+    public function testRecvBytesWrapsSocketException(): void
+    {
+        $client = new SocketExceptionClient(new ThrowingSocket());
+
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Error reading data from socket');
+        $client->exposeRecvBytes(100);
+    }
+
+    public function testSendCmdWrapsSocketExceptionFromGetStatus(): void
+    {
+        $client = new SocketExceptionClient(new ThrowingSocket());
+
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Connection reset');
+        $client->exposeSendCmd('LISTSCRIPTS');
+    }
+
+    public function testSendCmdWrapsSocketExceptionFromWrite(): void
+    {
+        $client = new SocketExceptionClient(new ThrowingWriteSocket());
+
+        $this->expectException(Exception::class);
+        $this->expectExceptionMessage('Broken pipe');
+        $client->exposeSendCmd('LISTSCRIPTS');
+    }
+
+    public function testWrappedExceptionPreservesOriginal(): void
+    {
+        $client = new SocketExceptionClient(new ThrowingSocket());
+
+        try {
+            $client->exposeRecvLn();
+            $this->fail('Expected ManageSieve\Exception');
+        } catch (Exception $e) {
+            $this->assertInstanceOf(
+                SocketClientException::class,
+                $e->getPrevious(),
+                'Original SocketClientException should be preserved as previous exception'
+            );
+        }
+    }
+}