Fix issue of json path names

Author: Pouya Yarandi

Sources/SwiftProtobuf/NameMap.swift

@@ -281,6 +281,6 @@ public struct _NameMap: ExpressibleByDictionaryLiteral {
 
   /// Returns all proto names
   internal var names: [Name] {
-    protoToNumberMap.map(\.key)
+    numberToNameMap.map(\.value.proto)
   }
 }

Sources/SwiftProtobuf/PathDecoder.swift

@@ -35,9 +35,15 @@ extension Message {
     guard let type = Self.self as? any _ProtoNameProviding.Type else {
       return nil
     }
-    return Array(field.utf8).withUnsafeBytes { bytes in
+    guard let number = Array(field.utf8).withUnsafeBytes({ bytes in
       type._protobuf_nameMap.number(forProtoName: bytes)
+    }) else {
+      return nil
+    }
+    if type._protobuf_nameMap.names(for: number)?.proto.description != field {
+      return nil
     }
+    return number
   }
 
   static func name(for field: Int) -> String? {

Tests/SwiftProtobufTests/Test_FieldMask.swift

@@ -334,6 +334,15 @@ final class Test_FieldMask: XCTestCase, PBTestHelpers {
         XCTAssertThrowsError(try Google_Protobuf_FieldMask(fieldNumbers: [10], of: SwiftProtoTesting_TestAny.self))
     }
 
+    // Checks that json names of paths should not be contained in mask field with allFieldsOf init.
+    func testFieldMaskAllPathsWithUniqueName() {
+        let mask = Google_Protobuf_FieldMask(allFieldsOf: SwiftProtoTesting_Fuzz_Message.self)
+        // proto name is included
+        XCTAssertTrue(mask.paths.contains("SingularGroup"))
+        // json name is not included
+        XCTAssertFalse(mask.paths.contains("singulargroup"))
+    }
+
     // Checks `union` func of fieldMask.
     func testUnionFieldMasks() throws {
         let m1 = Google_Protobuf_FieldMask(protoPaths: ["a", "b"])
@@ -787,4 +796,21 @@ final class Test_FieldMask: XCTestCase, PBTestHelpers {
         try m1.merge(with: m2, fieldMask: .init(protoPaths: ["SingularGroup.group_field"]))
         XCTAssertEqual(m1.singularGroup.groupField, m2.singularGroup.groupField)
     }
+
+    // Checks that merging with json path should do nothing. Path should only be merged using proto names.
+    func testMergeFieldWithJSONName() throws {
+        var m1 = SwiftProtoTesting_Fuzz_Message()
+        let m2 = SwiftProtoTesting_Fuzz_Message.with { m in
+            m.singularGroup = .with { $0.groupField = 1 }
+        }
+        // should do nothing with json path (should not merge)
+        try m1.merge(with: m2, fieldMask: .with({ $0.paths = ["singulargroup"] }))
+        XCTAssertNotEqual(m1.singularGroup, m2.singularGroup)
+        // should merge with proto path
+        try m1.merge(with: m2, fieldMask: .with({ $0.paths = ["SingularGroup"] }))
+        XCTAssertEqual(m1.singularGroup, m2.singularGroup)
+        // should do nothing with json path (do not clear field)
+        try m1.merge(with: m2, fieldMask: .with({ $0.paths = ["singulargroup"] }))
+        XCTAssertEqual(m1.singularGroup, m2.singularGroup)
+    }
 }