[compat] implement Store#add_path for certificate lookup

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kares

src/main/java/org/jruby/ext/openssl/X509Store.java

@@ -166,13 +166,26 @@ static RubyTime toTime(final ThreadContext context, final IRubyObject arg) {
 
     @JRubyMethod
     public IRubyObject add_path(final ThreadContext context, final IRubyObject arg) {
-        warn(context, "WARNING: unimplemented method called: OpenSSL::X509::Store#add_path");
-        return context.nil;
+        String path = arg.convertToString().toString();
+        final Ruby runtime = context.runtime;
+        try {
+            if (store.loadLocations(runtime, null, path) != 1) {
+                throw newStoreError(runtime, "X509_LOOKUP_add_dir");
+            }
+        }
+        catch (RaiseException e) {
+            throw e;
+        }
+        catch (Exception e) {
+            debugStackTrace(runtime, e);
+            throw newStoreError(runtime, "loading path failed: ", e);
+        }
+        return this;
     }
 
     @JRubyMethod
     public IRubyObject add_file(final IRubyObject arg) {
-        String file = arg.toString();
+        String file = arg.convertToString().toString();
         final Ruby runtime = getRuntime();
         try {
             if (store.loadLocations(runtime, file, null) != 1) {

src/test/ruby/x509/test_x509store.rb

@@ -141,6 +141,22 @@ def test_store_dup_clone_not_allowed
     assert_raise(NoMethodError) { store.clone }
   end
 
+  def test_add_path_returns_self
+    store = OpenSSL::X509::Store.new
+    assert_equal store, store.add_path("/etc/ssl/certs")
+  end
+
+  def test_add_path_raises_with_empty_string
+    store = OpenSSL::X509::Store.new
+    assert_raise(OpenSSL::X509::StoreError) { store.add_path("") }
+  end
+
+  def test_add_path_accepts_nonexistent_dir
+    store = OpenSSL::X509::Store.new
+    # CRuby accepts non-existent dirs (lazy lookup at verify time)
+    assert_equal store, store.add_path("/nonexistent/path/to/certs")
+  end
+
   def test_use_non_existing_cert_file
     ENV['SSL_CERT_FILE'] = 'non-existing-file.crt'
     store = OpenSSL::X509::Store.new