fix(native): record an empty Objective-C protocol name as a protocol failure (#4078)

* fix(native): record an empty Objective-C protocol name as a protocol failure

A protocol declaration whose name was an empty NUL-terminated string was
accepted as decoded, so whole-result validation of objc_protocols[].name
failed and inspect-native-dispatch-metadata discarded every decoded
class from the same image. The protocol decoder now rejects the empty
name inside its per-protocol boundary, as the class decoder already
does, so the protocol becomes a recorded partial-coverage failure and
independently decoded classes are retained.

Fixes #3873

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(native): decode adopted protocols before rejecting an empty parent name

Review follow-up. The empty-name check ran before the adopted-protocol
list was traversed, so a protocol declared only through an empty-named
parent's list was dropped. Adopted protocols are independent
declarations; traverse the list first, then reject only the parent.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

src/native/AppleDispatchMetadata.test.ts

@@ -851,4 +851,50 @@ describe("Apple dispatch list scan budget", () => {
     );
     expect(coverage?.reason).not.toContain("max_records_reached");
   });
+
+  it.each([
+    ["RetainedProtocol", ["RetainedProtocol"], "complete"],
+    ["", [], "partial"],
+  ])(
+    "keeps the class when the protocol name is %j",
+    (protocolName, protocols, status) => {
+      const bytes = unmappedProtocolImage("neither");
+      bytes.writeBigUInt64LE(unmappedProtocolSectionBase + 0x700n, 0x300);
+      bytes.writeBigUInt64LE(unmappedProtocolSectionBase + 0x800n, 0x708);
+      bytes.writeUInt32LE(72, 0x740);
+      bytes.write(`${protocolName}\0`, 0x800);
+      const result = decodeAppleDispatchMetadata(bytes, 100, provenance);
+      expect(result.objc_classes).toMatchObject([{ name: "RetainedClass" }]);
+      expect(result.objc_protocols.map(({ name }) => name)).toEqual(protocols);
+      const coverage = unmappedProtocolClassCoverage(result);
+      expect(coverage).toMatchObject({ status });
+      if (status === "partial")
+        expect(coverage?.reason).toBe(
+          "Protocol 0x100000700: Objective-C protocol has an empty name",
+        );
+    },
+  );
+
+  it("keeps a protocol adopted only by an empty-named protocol", () => {
+    const bytes = unmappedProtocolImage("neither");
+    const at = (offset: bigint) => unmappedProtocolSectionBase + offset;
+    bytes.writeBigUInt64LE(at(0x700n), 0x300);
+    bytes.writeBigUInt64LE(at(0x800n), 0x708); // empty parent name
+    bytes.writeBigUInt64LE(at(0x900n), 0x710); // adopted protocol list
+    bytes.writeUInt32LE(72, 0x740);
+    bytes.writeBigUInt64LE(1n, 0x900);
+    bytes.writeBigUInt64LE(at(0xa00n), 0x908);
+    bytes.writeBigUInt64LE(at(0xb00n), 0xa08);
+    bytes.writeUInt32LE(72, 0xa40);
+    bytes.write("ChildProtocol\0", 0xb00);
+    const result = decodeAppleDispatchMetadata(bytes, 100, provenance);
+    expect(result.objc_classes).toMatchObject([{ name: "RetainedClass" }]);
+    expect(result.objc_protocols.map(({ name }) => name)).toEqual([
+      "ChildProtocol",
+    ]);
+    expect(unmappedProtocolClassCoverage(result)).toMatchObject({
+      status: "partial",
+      reason: "Protocol 0x100000700: Objective-C protocol has an empty name",
+    });
+  });
 });

src/native/AppleObjcProtocols.ts

@@ -67,7 +67,11 @@ export const createObjcProtocolReader = (input: {
       if (read.u32(address + 64n) < 72)
         throw new RangeError("Truncated Objective-C protocol declaration");
       const protocolName = name(address);
+      // Adopted protocols are independent declarations; decode them before
+      // rejecting a parent whose own name is empty.
       const adopted = list(read.pointer(address + 16n));
+      if (protocolName.length === 0)
+        throw new TypeError("Objective-C protocol has an empty name");
       const required = [
         ...methods(read.pointer(address + 24n), true, true),
         ...methods(read.pointer(address + 32n), true, false),