Merge pull request #1513 from thomasvl/message_set_fix_1_x

Fix ordering bug in MessageSet parsing (1.x branch)

Author: tbkka

Sources/SwiftProtobuf/BinaryDecoder.swift

@@ -1213,7 +1213,7 @@ internal struct BinaryDecoder: Decoder {
                         extDecoder.fieldWireFormat = .lengthDelimited
                         try extDecoder.decodeExtensionField(values: &values,
                                                             messageType: messageType,
-                                                            fieldNumber: fieldNumber,
+                                                            fieldNumber: ext.fieldNumber,
                                                             messageExtension: ext)
                         wasDecoded = extDecoder.consumed
                       }

Tests/SwiftProtobufTests/Test_MessageSet.swift

@@ -144,6 +144,44 @@ class Test_MessageSet: XCTestCase {
     "}\n"
   )
 
+  func testParseOrder1() throws {
+    let serialized = Data([11,
+        16, 176, 166, 94, // Extension ID
+        26, 2, 120, 123, // Payload message
+        12])
+
+    let msg: Proto2WireformatUnittest_TestMessageSet
+    do {
+      msg = try Proto2WireformatUnittest_TestMessageSet(
+        serializedData: serialized,
+        extensions: ProtobufUnittest_UnittestMset_Extensions)
+    } catch let e {
+      XCTFail("Failed to parse: \(e)")
+      return
+    }
+    XCTAssertEqual(
+      msg.ProtobufUnittest_TestMessageSetExtension1_messageSetExtension.i, 123)
+  }
+
+  func testParseOrder2() throws {
+    let serialized = Data([11,
+        26, 2, 120, 123, // Payload message
+        16, 176, 166, 94, // Extension ID
+        12])
+
+    let msg: Proto2WireformatUnittest_TestMessageSet
+    do {
+      msg = try Proto2WireformatUnittest_TestMessageSet(
+        serializedData: serialized,
+        extensions: ProtobufUnittest_UnittestMset_Extensions)
+    } catch let e {
+      XCTFail("Failed to parse: \(e)")
+      return
+    }
+    XCTAssertEqual(
+      msg.ProtobufUnittest_TestMessageSetExtension1_messageSetExtension.i, 123)
+  }
+
   // text_format_unittest.cc: TEST_F(TextFormatMessageSetTest, Serialize)
   func testTextFormat_Serialize() {
     let msg = ProtobufUnittest_TestMessageSetContainer.with {