Fix remapping forge dependencies

src/main/java/net/fabricmc/loom/providers/MinecraftMappedProvider.java

@@ -175,7 +175,7 @@ public class MinecraftMappedProvider extends DependencyProvider {
 				}
 
 				TinyTree yarnWithSrg = getExtension().getMappingsProvider().getMappingsWithSrg();
-				AtRemapper.remap(output, yarnWithSrg);
+				AtRemapper.remap(getProject().getLogger(), output, yarnWithSrg);
 				CoreModClassRemapper.remapJar(output, yarnWithSrg, getProject().getLogger());
 			}
 		}

src/main/java/net/fabricmc/loom/util/ModCompileRemapper.java

@@ -73,7 +73,7 @@ public class ModCompileRemapper {
 				String version = artifact.getModuleVersion().getId().getVersion();
 				String classifierSuffix = artifact.getClassifier() == null ? "" : (":" + artifact.getClassifier());
 
-				if (!isFabricMod(logger, artifact)) {
+				if (!shouldRemapMod(logger, artifact, extension.isForge())) {
 					addToRegularCompile(project, regularConfig, artifact);
 					continue;
 				}
@@ -112,13 +112,20 @@ public class ModCompileRemapper {
 	/**
 	 * Checks if an artifact is a fabric mod, according to the presence of a fabric.mod.json.
 	 */
-	private static boolean isFabricMod(Logger logger, ResolvedArtifact artifact) {
+	private static boolean shouldRemapMod(Logger logger, ResolvedArtifact artifact, boolean forge) {
 		File input = artifact.getFile();
 
 		try (ZipFile zipFile = new ZipFile(input)) {
-			if (zipFile.getEntry("fabric.mod.json") != null) {
-				logger.info("Found Fabric mod in modCompile: {}", artifact.getId());
-				return true;
+			if (forge) {
+				if (zipFile.getEntry("META-INF/mods.toml") != null) {
+					logger.info("Found Forge mod in modCompile: {}", artifact.getId());
+					return true;
+				}
+			} else {
+				if (zipFile.getEntry("fabric.mod.json") != null) {
+					logger.info("Found Fabric mod in modCompile: {}", artifact.getId());
+					return true;
+				}
 			}
 
 			return false;

src/main/java/net/fabricmc/loom/util/ModProcessor.java

@@ -100,6 +100,7 @@ public class ModProcessor {
 	}
 
 	private static void stripNestedJars(File file) {
+		if (!ZipUtil.containsEntry(file, "fabric.mod.json")) return;
 		// Strip out all contained jar info as we dont want loader to try and load the jars contained in dev.
 		ZipUtil.transformEntries(file, new ZipEntryTransformerEntry[] {(new ZipEntryTransformerEntry("fabric.mod.json", new StringZipEntryTransformer() {
 			@Override
@@ -203,7 +204,7 @@ public class ModProcessor {
 			}
 
 			if (extension.isForge()) {
-				AtRemapper.remap(info.getRemappedOutput().toPath(), mappings);
+				AtRemapper.remap(project.getLogger(), info.getRemappedOutput().toPath(), mappings);
 				CoreModClassRemapper.remapJar(info.getRemappedOutput().toPath(), mappings, project.getLogger());
 			}
 		}

src/main/java/net/fabricmc/loom/util/srg/AtRemapper.java

@@ -37,6 +37,8 @@ import com.google.common.collect.ImmutableMap;
 
 import net.fabricmc.loom.util.function.CollectionUtil;
 import net.fabricmc.mapping.tree.TinyTree;
+import org.apache.commons.lang3.StringUtils;
+import org.gradle.api.logging.Logger;
 
 /**
  * Remaps AT classes from SRG to Yarn.
@@ -44,7 +46,7 @@ import net.fabricmc.mapping.tree.TinyTree;
  * @author Juuz
  */
 public final class AtRemapper {
-	public static void remap(Path jar, TinyTree mappings) throws IOException {
+	public static void remap(Logger logger, Path jar, TinyTree mappings) throws IOException {
 		try (FileSystem fs = FileSystems.newFileSystem(URI.create("jar:" + jar.toUri()), ImmutableMap.of("create", false))) {
 			Path atPath = fs.getPath("META-INF", "accesstransformer.cfg");
 
@@ -55,12 +57,17 @@ public final class AtRemapper {
 				for (int i = 0; i < lines.size(); i++) {
 					String line = lines.get(i).trim();
 
-					if (line.startsWith("#")) {
+					if (line.startsWith("#") || StringUtils.isBlank(line)) {
 						output.add(i, line);
 						continue;
 					}
 
 					String[] parts = line.split(" ");
+					if (parts.length < 3) {
+						logger.warn("Invalid AT Line: " + line);
+						output.add(i, line);
+						continue;
+					}
 					String name = parts[1].replace('.', '/');
 					parts[1] = CollectionUtil.find(
 							mappings.getClasses(),