Attempted fix for #47

src/main/java/net/fabricmc/tinyremapper/AsmClassRemapper.java

@@ -18,8 +18,10 @@
 package net.fabricmc.tinyremapper;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
 
 import javax.lang.model.SourceVersion;
@@ -48,7 +50,6 @@
 class AsmClassRemapper extends ClassRemapper {
 	public AsmClassRemapper(ClassVisitor cv, AsmRemapper remapper, boolean checkPackageAccess, boolean skipLocalMapping, boolean renameInvalidLocals) {
 		super(cv, remapper);
-
 		this.checkPackageAccess = checkPackageAccess;
 		this.skipLocalMapping = skipLocalMapping;
 		this.renameInvalidLocals = renameInvalidLocals;
@@ -72,7 +73,33 @@ public MethodVisitor visitMethod(int access, String name, String descriptor, Str
 			methodNode = new MethodNode(api, access, name, descriptor, signature, exceptions);
 		}
 
-		return super.visitMethod(access, name, descriptor, signature, exceptions);
+		String remappedDescriptor = remapper.mapMethodDesc(descriptor);
+		Collection<String> names = ((AsmRemapper) remapper).mapMultiMethodName(className, name, descriptor);
+		MethodVisitor visitor;
+
+		if(names.size() == 1) {
+			visitor = this.cv.visitMethod(
+					access,
+					names.iterator().next(),
+					remappedDescriptor,
+					remapper.mapSignature(signature, false),
+					exceptions == null ? null : remapper.mapTypes(exceptions));
+		} else {
+			List<MethodVisitor> visitorList = new ArrayList<>();
+
+			for(String newName : names) {
+				visitorList.add(this.cv.visitMethod(
+						access,
+						newName,
+						remappedDescriptor,
+						remapper.mapSignature(signature, false),
+						exceptions == null ? null : remapper.mapTypes(exceptions)));
+			}
+
+			visitor = new MultiMethodVisitor(api, visitorList);
+		}
+
+		return visitor == null ? null : createMethodRemapper(visitor);
 	}
 
 	@Override

src/main/java/net/fabricmc/tinyremapper/AsmRemapper.java

@@ -17,6 +17,13 @@
 
 package net.fabricmc.tinyremapper;
 
+import java.util.AbstractCollection;
+import java.util.AbstractList;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
 import java.util.Locale;
 
 import org.objectweb.asm.commons.Remapper;
@@ -53,23 +60,60 @@ public String mapFieldName(String owner, String name, String desc) {
 		return remapper.extraRemapper != null ? remapper.extraRemapper.mapFieldName(owner, name, desc) : name;
 	}
 
+	public Collection<String> mapMultiMethodName(String owner, String name, String desc) {
+		ClassInstance cls = getClass(owner);
+		if (cls == null) return Collections.singletonList(name);
+		List<MemberInstance> instances = cls.multiResolve(MemberType.METHOD, MemberInstance.getMethodId(name, desc));
+		if(instances.isEmpty()) {
+			return Collections.singletonList(mapMember(null, owner, name, desc));
+		} else {
+			return new AbstractCollection<String>() {
+				@Override
+				public Iterator<String> iterator() {
+					return new Iterator<String>() {
+						Iterator<MemberInstance> members = instances.iterator();
+						@Override
+						public boolean hasNext() {
+							return members.hasNext();
+						}
+
+						@Override
+						public String next() {
+							return mapMember(members.next(), owner, name, desc);
+						}
+					};
+				}
+
+				@Override
+				public int size() {
+					return instances.size();
+				}
+			};
+		}
+	}
+
 	@Override
 	public String mapMethodName(String owner, String name, String desc) {
 		ClassInstance cls = getClass(owner);
 		if (cls == null) return name; // TODO: try to map these from just the mappings?, warn if actual class is missing
 
 		MemberInstance member = cls.resolve(MemberType.METHOD, MemberInstance.getMethodId(name, desc));
+		return mapMember(member, owner, name, desc);
+	}
+
+	protected String mapMember(MemberInstance member, String srcOwner, String srcName, String srcDesc) {
 		String newName;
 
 		if (member != null && (newName = member.getNewName()) != null) {
 			return newName;
 		}
 
-		assert (newName = remapper.methodMap.get(owner+"/"+MemberInstance.getMethodId(name, desc))) == null || newName.equals(name);
+		assert (newName = remapper.methodMap.get(srcOwner+"/"+MemberInstance.getMethodId(srcName, srcDesc))) == null || newName.equals(srcName);
 
-		return remapper.extraRemapper != null ? remapper.extraRemapper.mapMethodName(owner, name, desc) : name;
+		return remapper.extraRemapper != null ? remapper.extraRemapper.mapMethodName(srcOwner, srcName, srcDesc) : srcName;
 	}
 
+
 	public String mapMethodNamePrefixDesc(String owner, String name, String descPrefix) {
 		ClassInstance cls = getClass(owner);
 		if (cls == null) return name;

src/main/java/net/fabricmc/tinyremapper/ClassInstance.java

@@ -19,13 +19,15 @@
 
 import java.nio.file.Path;
 import java.util.ArrayDeque;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Deque;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.IdentityHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -218,15 +220,16 @@ void propagate(TinyRemapper remapper, MemberType type, String originatingCls, St
 		 * different branches of the hierarchy tree that were not visited before may access it.
 		 */
 
-		if (dir == Direction.ANY || dir == Direction.UP || isVirtual && member != null && (member.access & (Opcodes.ACC_STATIC | Opcodes.ACC_PRIVATE)) == 0) {
+		boolean trueVirtual = isVirtual && member != null && (member.access & (Opcodes.ACC_STATIC | Opcodes.ACC_PRIVATE)) == 0;
+		if (dir == Direction.ANY || dir == Direction.UP || trueVirtual) {
 			for (ClassInstance node : parents) {
 				if (visitedUp.add(node)) {
-					node.propagate(remapper, type, originatingCls, idSrc, nameDst, Direction.UP, isVirtual, false, visitedUp, visitedDown);
+					node.propagate(remapper, type, originatingCls, idSrc, nameDst, Direction.UP, true, false, visitedUp, visitedDown);
 				}
 			}
 		}
 
-		if (dir == Direction.ANY || dir == Direction.DOWN || isVirtual && member != null && (member.access & (Opcodes.ACC_STATIC | Opcodes.ACC_PRIVATE)) == 0) {
+		if (dir == Direction.ANY || dir == Direction.DOWN || trueVirtual) {
 			for (ClassInstance node : children) {
 				if (visitedDown.add(node)) {
 					node.propagate(remapper, type, originatingCls, idSrc, nameDst, Direction.DOWN, isVirtual, false, visitedUp, visitedDown);
@@ -236,6 +239,16 @@ void propagate(TinyRemapper remapper, MemberType type, String originatingCls, St
 	}
 
 	public MemberInstance resolve(MemberType type, String id) {
+		return resolve(type, id, null);
+	}
+
+	public List<MemberInstance> multiResolve(MemberType type, String id) {
+		List<MemberInstance> created = new ArrayList<>();
+		this.resolve(type, id, created);
+		return created;
+	}
+
+	public MemberInstance resolve(MemberType type, String id, List<MemberInstance> multiResolve) {
 		MemberInstance member = getMember(type, id);
 		if (member != null) return member;
 
@@ -244,7 +257,7 @@ public MemberInstance resolve(MemberType type, String id) {
 
 		if (member == null) {
 			// compute
-			member = resolve0(type, id);
+			member = resolve0(type, id, multiResolve);
 			assert member != null;
 
 			// put in cache
@@ -255,7 +268,7 @@ public MemberInstance resolve(MemberType type, String id) {
 		return member != nullMember ? member : null;
 	}
 
-	private MemberInstance resolve0(MemberType type, String id) {
+	private MemberInstance resolve0(MemberType type, String id, List<MemberInstance> multiResolve) {
 		boolean isField = type == MemberType.FIELD;
 		Set<ClassInstance> visited = Collections.newSetFromMap(new IdentityHashMap<>());
 		Deque<ClassInstance> queue = new ArrayDeque<>();
@@ -274,9 +287,15 @@ private MemberInstance resolve0(MemberType type, String id) {
 				for (ClassInstance parent : cls.parents) {
 					if (parent.isInterface() == isField && visited.add(parent)) {
 						MemberInstance ret = parent.getMember(type, id);
-						if (ret != null) return ret;
-
-						queue.addLast(parent);
+						if (ret != null) {
+							if(multiResolve == null) {
+								return ret;
+							} else {
+								multiResolve.add(ret);
+							}
+						} else {
+							queue.addLast(parent);
+						}
 					}
 				}
 			} while ((cls = queue.pollLast()) != null);
@@ -310,7 +329,12 @@ private MemberInstance resolve0(MemberType type, String id) {
 								if (!isField && (parentMember.access & (Opcodes.ACC_ABSTRACT)) != 0) {
 									secondaryMatch = parentMember;
 								} else {
-									return parentMember;
+									if(multiResolve == null) {
+										return parentMember;
+									} else {
+										multiResolve.add(parentMember);
+										continue;
+									}
 								}
 							}
 						}
@@ -321,7 +345,12 @@ private MemberInstance resolve0(MemberType type, String id) {
 			} while (!isField && (cls = queue.pollFirst()) != null);
 		} while ((context = queue.pollFirst()) != null); // overall-recursion for fields
 
-		return secondaryMatch != null ? secondaryMatch : nullMember;
+		if(multiResolve == null) {
+			return secondaryMatch != null ? secondaryMatch : nullMember;
+		} else {
+			multiResolve.add(secondaryMatch);
+			return nullMember;
+		}
 	}
 
 	public MemberInstance resolvePartial(MemberType type, String name, String descPrefix) {

src/main/java/net/fabricmc/tinyremapper/MetaInfFixer.java

@@ -0,0 +1,128 @@
+package net.fabricmc.tinyremapper;
+
+import java.io.BufferedOutputStream;
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.Iterator;
+import java.util.jar.Attributes;
+import java.util.jar.Manifest;
+
+public class MetaInfFixer implements OutputConsumerPath.ResourceRemapper {
+	public static final MetaInfFixer INSTANCE = new MetaInfFixer();
+
+	protected MetaInfFixer() {}
+
+	@Override
+	public boolean canTransform(TinyRemapper remapper, Path relativePath) {
+		return shouldStripForFixMeta(relativePath) ||
+		       relativePath.getFileName().toString().equals("MANIFEST.MF") ||
+		       (remapper != null && relativePath.getNameCount() == 3 && relativePath.getName(1).toString().equals("services"));
+	}
+
+	@Override
+	public void transform(Path destinationDirectory, Path relativePath, InputStream input, TinyRemapper remapper) throws IOException {
+		String fileName = relativePath.getFileName().toString();
+		if (fileName.equals("MANIFEST.MF")) {
+			Manifest manifest = new Manifest(input);
+			fixManifest(manifest, remapper);
+			try (OutputStream os = new BufferedOutputStream(Files.newOutputStream(destinationDirectory.resolve(relativePath)))) {
+				manifest.write(os);
+			}
+		} else if (remapper != null && relativePath.getNameCount() == 3 && relativePath.getName(1).toString().equals("services")) {
+			fileName = mapFullyQualifiedClassName(fileName, remapper);
+			Path newFile = destinationDirectory.resolve(relativePath).getParent().resolve(fileName);
+			try (BufferedReader reader = new BufferedReader(new InputStreamReader(input));
+			     BufferedWriter writer = Files.newBufferedWriter(newFile, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE)) {
+				fixServiceDecl(reader, writer, remapper);
+			}
+		}
+	}
+
+	private static boolean shouldStripForFixMeta(Path file) {
+		if (file.getNameCount() != 2) return false; // not directly inside META-INF dir
+
+		assert file.getName(0).toString().equals("META-INF");
+
+		String fileName = file.getFileName().toString();
+
+		// https://docs.oracle.com/en/java/javase/12/docs/specs/jar/jar.html#signed-jar-file
+		return fileName.endsWith(".SF")
+		       || fileName.endsWith(".DSA")
+		       || fileName.endsWith(".RSA")
+		       || fileName.startsWith("SIG-");
+	}
+
+	private static String mapFullyQualifiedClassName(String name, TinyRemapper remapper) {
+		assert name.indexOf('/') < 0;
+
+		return remapper.mapClass(name.replace('.', '/')).replace('/', '.');
+	}
+
+	private static void fixManifest(Manifest manifest, TinyRemapper remapper) {
+		Attributes mainAttrs = manifest.getMainAttributes();
+
+		if (remapper != null) {
+			String val = mainAttrs.getValue(Attributes.Name.MAIN_CLASS);
+			if (val != null) mainAttrs.put(Attributes.Name.MAIN_CLASS, mapFullyQualifiedClassName(val, remapper));
+
+			val = mainAttrs.getValue("Launcher-Agent-Class");
+			if (val != null) mainAttrs.put("Launcher-Agent-Class", mapFullyQualifiedClassName(val, remapper));
+		}
+
+		mainAttrs.remove(Attributes.Name.SIGNATURE_VERSION);
+
+		for (Iterator<Attributes> it = manifest.getEntries().values().iterator(); it.hasNext(); ) {
+			Attributes attrs = it.next();
+
+			for (Iterator<Object> it2 = attrs.keySet().iterator(); it2.hasNext(); ) {
+				Attributes.Name attrName = (Attributes.Name) it2.next();
+				String name = attrName.toString();
+
+				if (name.endsWith("-Digest") || name.contains("-Digest-") || name.equals("Magic")) {
+					it2.remove();
+				}
+			}
+
+			if (attrs.isEmpty()) it.remove();
+		}
+	}
+
+	private static void fixServiceDecl(BufferedReader reader, BufferedWriter writer, TinyRemapper remapper) throws IOException {
+		String line;
+
+		while ((line = reader.readLine()) != null) {
+			int end = line.indexOf('#');
+			if (end < 0) end = line.length();
+
+			// trim start+end to skip ' ' and '\t'
+
+			int start = 0;
+			char c;
+
+			while (start < end && ((c = line.charAt(start)) == ' ' || c == '\t')) {
+				start++;
+			}
+
+			while (end > start && ((c = line.charAt(end - 1)) == ' ' || c == '\t')) {
+				end--;
+			}
+
+			if (start == end) {
+				writer.write(line);
+			} else {
+				writer.write(line, 0, start);
+				writer.write(mapFullyQualifiedClassName(line.substring(start, end), remapper));
+				writer.write(line, end, line.length() - end);
+			}
+
+			writer.newLine();
+		}
+	}
+}

src/main/java/net/fabricmc/tinyremapper/MetaInfRemover.java

@@ -0,0 +1,19 @@
+package net.fabricmc.tinyremapper;
+
+import java.io.InputStream;
+import java.nio.file.Path;
+
+public class MetaInfRemover implements OutputConsumerPath.ResourceRemapper {
+	public static final MetaInfRemover INSTANCE = new MetaInfRemover();
+
+	protected MetaInfRemover() {}
+
+	@Override
+	public boolean canTransform(TinyRemapper remapper, Path relativePath) {
+		return relativePath.startsWith("META-INF") && relativePath.getNameCount() != 2;
+	}
+
+	@Override
+	public void transform(Path destinationDirectory, Path relativePath, InputStream input, TinyRemapper remapper) {
+	}
+}