fix(jruby): Schema#validate should not accumulate errors in @errors (#…

…3258)

**What problem is this PR intended to solve?**

Fixes #1282

**Have you included adequate test coverage?**

Yes.

**Does this change affect the behavior of either the C or the Java
implementations?**

Brings the JRuby impl in line with the CRuby impl.

CHANGELOG.md

@@ -39,6 +39,8 @@ Nokogiri follows [Semantic Versioning](https://semver.org/), please see the [REA
 * [CRuby] Update node GC lifecycle to avoid a potential memory leak with fragments in libxml 2.13.0 caused by changes in `xmlAddChild`. [#3156] @flavorjones
 * [CRuby] libgumbo correctly prints nonstandard element names in error messages. [#3219] @stevecheckoway
 * [JRuby] Fixed some bugs in how `Node#attributes` handles attributes with namespaces. [#2677, #2679] @flavorjones
+* [JRuby] Fix `Schema#validate` to only return the most recent Document's errors. Previously, if multiple documents were validated, this method returned the accumulated errors of all previous documents. [#1282] @flavorjones
+* [JRuby] Fix `Schema#validate` to not clobber the `@errors` instance variable. [#1282] @ flavorjones
 
 
 ### Changed

ext/java/nokogiri/XmlSchema.java

@@ -222,7 +222,7 @@ public class XmlSchema extends RubyObject
   IRubyObject
   validate_document_or_file(ThreadContext context, XmlDocument xmlDocument)
   {
-    RubyArray<?> errors = (RubyArray) this.getInstanceVariable("@errors");
+    RubyArray errors = (RubyArray)context.runtime.newEmptyArray();
     ErrorHandler errorHandler = new SchemaErrorHandler(context.runtime, errors);
     setErrorHandler(errorHandler);
 

ext/nokogiri/xml_relax_ng.c

@@ -24,7 +24,7 @@ static const rb_data_type_t xml_relax_ng_type = {
  * Validate a Nokogiri::XML::Document against this RelaxNG schema.
  */
 static VALUE
-validate_document(VALUE self, VALUE document)
+noko_xml_relax_ng__validate_document(VALUE self, VALUE document)
 {
   xmlDocPtr doc;
   xmlRelaxNGPtr schema;
@@ -162,5 +162,5 @@ noko_init_xml_relax_ng(void)
   rb_define_singleton_method(cNokogiriXmlRelaxNG, "read_memory", read_memory, -1);
   rb_define_singleton_method(cNokogiriXmlRelaxNG, "from_document", from_document, -1);
 
-  rb_define_private_method(cNokogiriXmlRelaxNG, "validate_document", validate_document, 1);
+  rb_define_private_method(cNokogiriXmlRelaxNG, "validate_document", noko_xml_relax_ng__validate_document, 1);
 }

ext/nokogiri/xml_schema.c

@@ -17,12 +17,6 @@ static const rb_data_type_t xml_schema_type = {
   .flags = RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
 };
 
-/*
- * call-seq:
- *  validate_document(document)
- *
- * Validate a Nokogiri::XML::Document against this Schema.
- */
 static VALUE
 validate_document(VALUE self, VALUE document)
 {

test/xml/test_schema.rb

@@ -197,6 +197,47 @@ class TestNokogiriXMLSchema < Nokogiri::TestCase
         assert(xsd.valid?(valid_doc))
         refute(xsd.valid?(invalid_doc))
       end
+
+      describe "error handling" do
+        let(:xsd) do
+          <<~EOF
+            <?xml version="1.0" encoding="UTF-8"?>
+            <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
+              targetNamespace="http://www.example.org/contactExample">
+              <xs:element name="Contacts"></xs:element>
+            </xs:schema>
+          EOF
+        end
+
+        let(:good_xml) { %(<Contacts xmlns="http://www.example.org/contactExample"><Contact></Contact></Contacts>) }
+        let(:bad_xml) { %(<Contacts xmlns="http://www.example.org/wrongNs"><Contact></Contact></Contacts>) }
+
+        it "does not clobber @errors" do
+          schema = Nokogiri::XML::Schema.new(xsd)
+          bad_doc = Nokogiri::XML(bad_xml)
+
+          # assert on setup
+          assert_empty(schema.errors)
+          refute_empty(schema.validate(bad_doc))
+
+          # this is the bit under test
+          assert_empty(schema.errors)
+        end
+
+        it "returns only the most recent document's errors" do
+          # https://github.com/sparklemotion/nokogiri/issues/1282
+          schema = Nokogiri::XML::Schema.new(xsd)
+          good_doc = Nokogiri::XML(good_xml)
+          bad_doc = Nokogiri::XML(bad_xml)
+
+          # assert on setup
+          assert_empty(schema.validate(good_doc))
+          refute_empty(schema.validate(bad_doc))
+
+          # this is the bit under test
+          assert_empty(schema.validate(good_doc))
+        end
+      end
     end
 
     it "xsd_with_dtd" do