[Java] Fixes #12682

Author: diemol

java/src/org/openqa/selenium/remote/service/DriverService.java

@@ -194,6 +194,12 @@ public void start() throws IOException {
       if (process != null) {
         return;
       }
+      if (this.executable == null) {
+        if (getDefaultDriverOptions().getBrowserName().isEmpty()) {
+          throw new WebDriverException("Driver executable is null and browser name is not set.");
+        }
+        this.executable = DriverFinder.getPath(this, getDefaultDriverOptions()).getDriverPath();
+      }
       LOG.fine(String.format("Starting driver at %s with %s", this.executable, this.args));
       process = new CommandLine(this.executable, args.toArray(new String[] {}));
       process.setEnvironmentVariables(environment);

java/src/org/openqa/selenium/safari/SafariTechPreviewDriverService.java

@@ -105,7 +105,7 @@ public File getDriverExecutable() {
   }
 
   @Override
-  protected Capabilities getDefaultDriverOptions() {
+  public Capabilities getDefaultDriverOptions() {
     return new SafariOptions().setUseTechnologyPreview(true);
   }