From b918ef3bc07e068a6bca683bb2d78deaf51f36ef Mon Sep 17 00:00:00 2001
From: shedaniel <daniel@shedaniel.me>
Date: Sat, 2 Jan 2021 14:02:44 +0800
Subject: [PATCH] Filter jar signing info in MANIFEST.MF properly

---
 .../net/fabricmc/loom/util/ModProcessor.java  | 23 ++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/main/java/net/fabricmc/loom/util/ModProcessor.java b/src/main/java/net/fabricmc/loom/util/ModProcessor.java
index 21cb07c1..f35f7af7 100644
--- a/src/main/java/net/fabricmc/loom/util/ModProcessor.java
+++ b/src/main/java/net/fabricmc/loom/util/ModProcessor.java
@@ -213,7 +213,7 @@ public class ModProcessor {
 				if (ZipUtil.containsEntry(info.getRemappedOutput(), "META-INF/MANIFEST.MF")) {
 					ZipUtil.transformEntry(info.getRemappedOutput(), "META-INF/MANIFEST.MF", (in, zipEntry, out) -> {
 						Manifest manifest = new Manifest(in);
-						manifest.getEntries().clear();
+						fixManifest(manifest);
 						out.putNextEntry(new ZipEntry(zipEntry.getName()));
 						manifest.write(out);
 						out.closeEntry();
@@ -233,6 +233,27 @@ public class ModProcessor {
 		}
 	}
 
+	private static void fixManifest(Manifest manifest) {
+		Attributes mainAttrs = manifest.getMainAttributes();
+		
+		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();
+		}
+	}
+
 	static JsonObject readInstallerJson(File file, Project project) {
 		try {
 			LoomGradleExtension extension = project.getExtensions().getByType(LoomGradleExtension.class);