Support split client/server intermediary for old Minecraft versions

minecraft/src/main/java/net/fabricmc/loader/impl/game/minecraft/MinecraftGameProvider.java

@@ -48,6 +48,7 @@
 import net.fabricmc.loader.impl.game.minecraft.patch.TinyFDPatch;
 import net.fabricmc.loader.impl.game.patch.GameTransformer;
 import net.fabricmc.loader.impl.launch.FabricLauncher;
+import net.fabricmc.loader.impl.launch.MappingConfiguration;
 import net.fabricmc.loader.impl.metadata.BuiltinModMetadata;
 import net.fabricmc.loader.impl.metadata.ModDependencyImpl;
 import net.fabricmc.loader.impl.util.Arguments;
@@ -318,10 +319,19 @@ public void initialize(FabricLauncher launcher) {
 				obfJars.put("realms", realmsJar);
 			}
 
+			String sourceNamespace = "official";
+
+			MappingConfiguration mappingConfig = launcher.getMappingConfiguration();
+			List<String> mappingNamespaces = mappingConfig.getNamespaces();
+
+			if (mappingNamespaces != null && !mappingNamespaces.contains(sourceNamespace)) {
+				sourceNamespace = envType == EnvType.CLIENT ? "clientOfficial" : "serverOfficial";
+			}
+
 			obfJars = GameProviderHelper.deobfuscate(obfJars,
 					getGameId(), getNormalizedGameVersion(),
 					getLaunchDirectory(),
-					launcher);
+					launcher, sourceNamespace);
 
 			for (int i = 0; i < gameJars.size(); i++) {
 				Path newJar = obfJars.get(names[i]);

src/main/java/net/fabricmc/loader/impl/discovery/RuntimeModRemapper.java

@@ -50,11 +50,11 @@
 import net.fabricmc.loader.impl.util.SystemProperties;
 import net.fabricmc.loader.impl.util.log.Log;
 import net.fabricmc.loader.impl.util.log.LogCategory;
-import net.fabricmc.loader.impl.util.mappings.TinyRemapperMappingsHelper;
 import net.fabricmc.tinyremapper.InputTag;
 import net.fabricmc.tinyremapper.NonClassCopyMode;
 import net.fabricmc.tinyremapper.OutputConsumerPath;
 import net.fabricmc.tinyremapper.TinyRemapper;
+import net.fabricmc.tinyremapper.TinyUtils;
 import net.fabricmc.tinyremapper.extension.mixin.MixinExtension;
 
 public final class RuntimeModRemapper {
@@ -76,7 +76,7 @@ public static void remap(Collection<ModCandidate> modCandidates, Path tmpDir, Pa
 		FabricLauncher launcher = FabricLauncherBase.getLauncher();
 
 		TinyRemapper remapper = TinyRemapper.newRemapper()
-				.withMappings(TinyRemapperMappingsHelper.create(launcher.getMappingConfiguration().getMappings(), "intermediary", launcher.getTargetNamespace()))
+				.withMappings(TinyUtils.createMappingProvider(launcher.getMappingConfiguration().getMappings(), "intermediary", launcher.getTargetNamespace()))
 				.renameInvalidLocals(false)
 				.extension(new MixinExtension(remapMixins::contains))
 				.build();

src/main/java/net/fabricmc/loader/impl/game/GameProviderHelper.java

@@ -46,12 +46,12 @@
 import net.fabricmc.loader.impl.util.UrlUtil;
 import net.fabricmc.loader.impl.util.log.Log;
 import net.fabricmc.loader.impl.util.log.LogCategory;
-import net.fabricmc.loader.impl.util.mappings.TinyRemapperMappingsHelper;
 import net.fabricmc.mappingio.tree.MappingTree;
 import net.fabricmc.tinyremapper.InputTag;
 import net.fabricmc.tinyremapper.NonClassCopyMode;
 import net.fabricmc.tinyremapper.OutputConsumerPath;
 import net.fabricmc.tinyremapper.TinyRemapper;
+import net.fabricmc.tinyremapper.TinyUtils;
 
 public final class GameProviderHelper {
 	private GameProviderHelper() { }
@@ -156,6 +156,10 @@ public static final class FindResult {
 	private static boolean emittedInfo = false;
 
 	public static Map<String, Path> deobfuscate(Map<String, Path> inputFileMap, String gameId, String gameVersion, Path gameDir, FabricLauncher launcher) {
+		return deobfuscate(inputFileMap, gameId, gameVersion, gameDir, launcher, "official");
+	}
+
+	public static Map<String, Path> deobfuscate(Map<String, Path> inputFileMap, String gameId, String gameVersion, Path gameDir, FabricLauncher launcher, String sourceNamespace) {
 		Log.debug(LogCategory.GAME_REMAP, "Requesting deobfuscation of %s", inputFileMap);
 
 		if (launcher.isDevelopment()) { // in-dev is already deobfuscated
@@ -184,7 +188,7 @@ public static Map<String, Path> deobfuscate(Map<String, Path> inputFileMap, Stri
 			return inputFileMap;
 		}
 
-		if (!namespaces.contains(targetNamespace)) {
+		if (!namespaces.contains(targetNamespace) || !namespaces.contains(sourceNamespace)) {
 			Log.debug(LogCategory.GAME_REMAP, "Missing namespace in mappings, using input files");
 			return inputFileMap;
 		}
@@ -239,7 +243,7 @@ public static Map<String, Path> deobfuscate(Map<String, Path> inputFileMap, Stri
 
 		try {
 			Files.createDirectories(deobfJarDir);
-			deobfuscate0(inputFiles, outputFiles, tmpFiles, mappingConfig.getMappings(), targetNamespace, launcher);
+			deobfuscate0(inputFiles, outputFiles, tmpFiles, mappingConfig.getMappings(), sourceNamespace, targetNamespace, launcher);
 		} catch (IOException e) {
 			throw new RuntimeException("error remapping game jars "+inputFiles, e);
 		}
@@ -266,9 +270,9 @@ private static Path getDeobfJarDir(Path gameDir, String gameId, String gameVersi
 		return ret.resolve(versionDirName.toString().replaceAll("[^\\w\\-\\. ]+", "_"));
 	}
 
-	private static void deobfuscate0(List<Path> inputFiles, List<Path> outputFiles, List<Path> tmpFiles, MappingTree mappings, String targetNamespace, FabricLauncher launcher) throws IOException {
+	private static void deobfuscate0(List<Path> inputFiles, List<Path> outputFiles, List<Path> tmpFiles, MappingTree mappings, String sourceNamespace, String targetNamespace, FabricLauncher launcher) throws IOException {
 		TinyRemapper remapper = TinyRemapper.newRemapper()
-				.withMappings(TinyRemapperMappingsHelper.create(mappings, "official", targetNamespace))
+				.withMappings(TinyUtils.createMappingProvider(mappings, sourceNamespace, targetNamespace))
 				.rebuildSourceFilenames(true)
 				.build();