Fix NPE in generic connection init path (#633)

Author: aguibert

vertx-sql-client/src/main/java/io/vertx/sqlclient/SqlConnectOptions.java

@@ -37,7 +37,7 @@ public class SqlConnectOptions extends NetClientOptions {
   private boolean cachePreparedStatements = DEFAULT_CACHE_PREPARED_STATEMENTS;
   private int preparedStatementCacheMaxSize = DEFAULT_PREPARED_STATEMENT_CACHE_MAX_SIZE;
   private int preparedStatementCacheSqlLimit = DEFAULT_PREPARED_STATEMENT_CACHE_SQL_LIMIT;
-  private Map<String, String> properties;
+  private Map<String, String> properties = new HashMap<>(4);
 
   public SqlConnectOptions() {
     super();
@@ -60,7 +60,9 @@ public SqlConnectOptions(SqlConnectOptions other) {
     this.cachePreparedStatements = other.cachePreparedStatements;
     this.preparedStatementCacheMaxSize = other.preparedStatementCacheMaxSize;
     this.preparedStatementCacheSqlLimit = other.preparedStatementCacheSqlLimit;
-    this.properties = new HashMap<>(other.properties);
+    if (other.properties != null) {
+      this.properties = new HashMap<>(other.properties);
+    }
   }
 
   /**

vertx-sql-client/src/test/java/io/vertx/sqlclient/tck/DriverTestBase.java

@@ -107,6 +107,22 @@ public void testCreatePool04(TestContext ctx) {
     }));
   }
 
+  @Test
+  public void testCreatePool05(TestContext ctx) {
+    // The default options will be an instanceof the driver-specific class, so manually copy
+    // each option over onto a fresh generic options object to force the generic constructor path
+    SqlConnectOptions defaults = defaultOptions();
+    SqlConnectOptions opts = new SqlConnectOptions()
+          .setHost(defaults.getHost())
+          .setPort(defaults.getPort())
+          .setDatabase(defaults.getDatabase())
+          .setUser(defaults.getUser())
+          .setPassword(defaults.getPassword());
+    Pool.pool(opts).getConnection(ctx.asyncAssertSuccess(ar -> {
+      ar.close();
+    }));
+  }
+  
   @Test(expected = ServiceConfigurationError.class)
   public void testRejectCreatePool01(TestContext ctx) {
     Pool.pool(new BogusOptions());