[misc] Leaking socket file descriptors when using unix domain sockets…

… when path doesn't exist

src/main/java/org/mariadb/jdbc/client/impl/ConnectionHelper.java

@@ -127,7 +127,17 @@ public static Socket connectSocket(final Configuration conf, final HostAddress h
             conf.pipe() == null && conf.localSocket() == null
                 ? new InetSocketAddress(hostAddress.host, hostAddress.port)
                 : null;
-        socket.connect(sockAddr, conf.connectTimeout());
+        try {
+          socket.connect(sockAddr, conf.connectTimeout());
+        } catch (IOException ioe) {
+          // ensure closing unix socket if wrong file
+          try {
+            socket.close();
+          } catch (IOException e) {
+            // eat
+          }
+          throw ioe;
+        }
       }
       return socket;
 

src/test/java/org/mariadb/jdbc/integration/UnixsocketTest.java

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+// Copyright (c) 2012-2014 Monty Program Ab
+// Copyright (c) 2015-2021 MariaDB Corporation Ab
+
+package org.mariadb.jdbc.integration;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.sql.SQLNonTransientConnectionException;
+import java.util.Properties;
+import org.junit.jupiter.api.Assumptions;
+import org.junit.jupiter.api.Test;
+
+public class UnixsocketTest extends Common {
+  private final boolean isWindows = System.getProperty("os.name").toLowerCase().contains("win");
+
+  @Test
+  public void testConnectWithUnixSocketWhenDBNotUp() throws IOException {
+    Assumptions.assumeTrue(!isWindows);
+    String url = "jdbc:mariadb://localhost:3306";
+    Properties properties = new Properties();
+    properties.setProperty("localSocket", "/tmp/not_valid_socket");
+    properties.setProperty("localSocketAddress", "localhost");
+
+    java.sql.Driver driver = new org.mariadb.jdbc.Driver();
+
+    Runtime rt = Runtime.getRuntime();
+    // System.out.println("netstat-apnx | grep " + ProcessHandle.current().pid());
+    String[] commands = {"/bin/sh", "-c", "netstat -apnx | grep " + ProcessHandle.current().pid()};
+    Process proc = rt.exec(commands);
+
+    BufferedReader stdInput = new BufferedReader(new InputStreamReader(proc.getInputStream()));
+    int initialLines = 0;
+    while (stdInput.readLine() != null) {
+      initialLines++;
+    }
+    proc.destroy();
+
+    for (int i = 0; i < 10; i++) {
+      assertThrows(
+          SQLNonTransientConnectionException.class,
+          () -> {
+            driver.connect(url, properties);
+          });
+    }
+    proc = rt.exec(commands);
+    stdInput = new BufferedReader(new InputStreamReader(proc.getInputStream()));
+    int finalLines = 0;
+    while (stdInput.readLine() != null) {
+      finalLines++;
+    }
+    proc.destroy();
+    assertEquals(
+        finalLines,
+        initialLines,
+        "Error Leaking socket file descriptors. initial :"
+            + initialLines
+            + " but ending with "
+            + finalLines);
+  }
+}