[ox/mc] Fix MC read alloca in a loop

deps/ox/src/ox/mc/read.cpp

@@ -6,6 +6,14 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
+#include <ox/model/modelhandleradaptor.hpp>
+#include <ox/std/buffer.hpp>
+#include <ox/std/reader.hpp>
+
+#include "read.hpp"
+
 namespace ox {
 
+template class ModelHandlerInterface<MetalClawReaderTemplate<BufferReader>>;
+
 }

deps/ox/src/ox/mc/read.hpp

@@ -254,8 +254,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, HashMap<Stri
 				auto wkey = ox_malloca(keyLen + 1, char, 0);
 				auto wkeyPtr = wkey.get();
 				oxReturnError(handler.fieldCString("", &wkeyPtr, keyLen + 1));
-				oxReturnError(handler.field("", &val.operator[](wkey.get())));
-				return OxError(0);
+				return handler.field("", &val[wkey.get()]);
 			};
 			for (std::size_t i = 0; i < len; ++i) {
 				oxReturnError(loopBody(handler, *val));
@@ -550,4 +549,6 @@ Result<T> readMC(const Buffer &buff) noexcept {
 	return readMC<T>(buff.data(), buff.size());
 }
 
+extern template class ModelHandlerInterface<MetalClawReaderTemplate<BufferReader>>;
+
 }

deps/ox/src/ox/mc/write.hpp

@@ -359,15 +359,19 @@ constexpr Error MetalClawWriter<Writer>::field(const char*, const HashMap<String
 		ModelHandlerInterface handler{&writer};
 		// double len for both key and value
 		oxReturnError(handler.setTypeInfo("Map", 0, {}, len * 2));
-		// write the array
-		for (std::size_t i = 0; i < len; i++) {
-			const auto &key = keys[i];
+		// this loop body needs to be in a lambda because of the potential alloca call
+		constexpr auto loopBody = [](auto &handler, auto const&key, auto const&val) -> ox::Error {
 			const auto keyLen = ox_strlen(key);
 			auto wkey = ox_malloca(keyLen + 1, char, 0);
 			memcpy(wkey, key.c_str(), keyLen + 1);
 			oxReturnError(handler.fieldCString("", wkey.get(), keyLen));
-			oxRequireM(value, val->at(key));
-			oxReturnError(handler.field("", value));
+			oxRequireM(value, val.at(key));
+			return handler.field("", value);
+		};
+		// write the array
+		for (std::size_t i = 0; i < len; i++) {
+			auto const&key = keys[i];
+			oxReturnError(loopBody(handler, key, *val));
 		}
 		oxReturnError(writer.finalize());
 		fieldSet = true;