Cancel patch change for each non valid logical combination (#231)

* Cancel patch change for each non valid logical combination

* Update CMakeLists.txt

---------

Co-authored-by: Patrick Boettcher <p@yai.se>

src/json-validator.cpp

@@ -436,9 +436,12 @@ class logical_combination : public schema
 
 		for (auto &s : subschemata_) {
 			first_error_handler esub;
+			json_patch old_patch(patch);
 			s->validate(ptr, instance, patch, esub);
 			if (!esub)
 				count++;
+			else
+				patch = old_patch;
 
 			if (is_validate_complete(instance, ptr, e, esub, count))
 				return;

test/CMakeLists.txt

@@ -74,6 +74,10 @@ add_executable(issue-189-default-values issue-189-default-values.cpp)
 target_link_libraries(issue-189-default-values nlohmann_json_schema_validator)
 add_test(NAME issue-189-default-values COMMAND issue-189-default-values)
 
+add_executable(issue-229-oneof-default-values issue-229-oneof-default-values.cpp)
+target_link_libraries(issue-229-oneof-default-values nlohmann_json_schema_validator)
+add_test(NAME issue-229-oneof-default-values COMMAND issue-229-oneof-default-values)
+
 add_executable(issue-243-root-default-values issue-243-root-default-values.cpp)
 target_link_libraries(issue-243-root-default-values nlohmann_json_schema_validator)
 add_test(NAME issue-243-root-default-values COMMAND issue-243-root-default-values)

test/issue-229-oneof-default-values.cpp

@@ -0,0 +1,69 @@
+#include <iostream>
+#include <nlohmann/json-schema.hpp>
+
+using nlohmann::json;
+using nlohmann::json_uri;
+using nlohmann::json_schema::json_validator;
+
+static const json default_schema = R"(
+{
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "type": "object",
+    "oneOf": [
+        {
+            "type": "object",
+            "properties": {
+                "name": {
+                    "enum": "foo"
+                },
+                "code": {
+                    "const": 1,
+                    "default": 1
+                }
+            }
+        },
+        {
+            "type": "object",
+            "properties": {
+                "name": {
+                    "enum": "bar"
+                },
+                "code": {
+                    "const": 2,
+                    "default": 2
+                }
+            }
+        }
+    ]
+})"_json;
+
+static void loader(const json_uri &uri, json &schema)
+{
+	schema = default_schema;
+}
+
+int main(void)
+{
+	json_validator validator(loader);
+
+	validator.set_root_schema(default_schema);
+
+	json data = R"({"name": "bar"})"_json;
+	json expected = R"(
+        [
+            {
+                "op": "add",
+                "path": "/code",
+                "value": 2
+            }
+        ]
+    )"_json;
+
+	json patch = validator.validate(data);
+	if (patch != expected) {
+		std::cerr << "Patch contains wrong operation: '" << patch.dump() << "' instead of expected '" << expected.dump() << "'" << std::endl;
+		return 1;
+	}
+
+	return 0;
+}