Support deobf of arbitrarily nested jars (#12)

Author: SizableShrimp

.gitignore

@@ -4,6 +4,7 @@
 /repo/
 /.settings/
 /bin/
+/out/
 .classpath
 .project
 *.lzma

src/main/java/net/minecraftforge/installertools/SrgMcpRenamer.java

@@ -129,16 +129,14 @@ public String mapMethodName(final String owner, final String name, final String
                 Utils.copy(zin, zout);
             };
 
+            processors.add(new ZipEntryProcessor(ein -> ein.getName().startsWith("META-INF/jarjar/") && ein.getName().endsWith(".jar"),
+                    (ein, zin, zout) -> this.processNestedJar(processors, defaultProcessor, ein, zin, zout)));
+
             ByteArrayOutputStream memory = input.equals(output) ? new ByteArrayOutputStream() : null;
             try (ZipOutputStream zout = new ZipOutputStream(memory == null ? new FileOutputStream(output) : memory);
                 ZipInputStream in = new ZipInputStream(new FileInputStream(input))) {
 
-                forEachZipEntry(in, (ein, zin) -> processors.stream()
-                        .filter(it -> it.validate(ein))
-                        .findFirst()
-                        .map(ZipEntryProcessor::getProcessor)
-                        .orElse(defaultProcessor)
-                        .process(ein, zin, zout));
+                process(processors, defaultProcessor, in, zout);
             }
 
             if (memory != null)
@@ -151,6 +149,19 @@ public String mapMethodName(final String owner, final String name, final String
         }
     }
 
+    private void process(List<ZipEntryProcessor> processors, ZipWritingConsumer defaultProcessor, ZipInputStream in, ZipOutputStream zout) throws IOException {
+        forEachZipEntry(in, (ein, zin) -> {
+            for (ZipEntryProcessor processor : processors) {
+                if (processor.validate(ein)) {
+                    processor.getProcessor().process(ein, zin, zout);
+                    return;
+                }
+            }
+
+            defaultProcessor.process(ein, zin, zout);
+        });
+    }
+
     private void forEachZipEntry(ZipInputStream zin, ZipConsumer entryConsumer) throws IOException {
         String prevName = null;
         ZipEntry ein;
@@ -197,6 +208,14 @@ private void processManifest(final ZipEntry ein, final ZipInputStream zin, final
         log("Stripped Manifest of sha digests");
     }
 
+    private void processNestedJar(List<ZipEntryProcessor> processors, ZipWritingConsumer defaultProcessor, ZipEntry ein, ZipInputStream in, ZipOutputStream zout) throws IOException {
+        zout.putNextEntry(makeNewEntry(ein));
+        ZipInputStream nestedIn = new ZipInputStream(in);
+        ZipOutputStream nestedOut = new ZipOutputStream(zout);
+        process(processors, defaultProcessor, nestedIn, nestedOut);
+        nestedOut.finish();
+    }
+
     private boolean holdsSignatures(final ZipEntry ein) {
         return ein.getName().startsWith("META-INF/") && (ein.getName().endsWith(".SF") || ein.getName().endsWith(".RSA"));
     }