Fix adding duplicate enum codes

spec/core/EnumTag.spec.ts

@@ -73,6 +73,36 @@ describe('EnumTag', () => {
 			})
 		})
 
+		it('decode values from a dict with differing codes', () => {
+			const grid = HGrid.make([
+				new HDict({
+					name: 'a',
+					code: -1,
+				}),
+				new HDict({
+					name: 'x',
+					code: -1,
+				}),
+				new HDict({
+					name: 'b',
+					code: 9,
+				}),
+				new HDict({
+					name: 'b',
+					code: 10,
+				}),
+			])
+
+			const enumTag = new EnumTag(grid)
+
+			expect(enumTag.nameToCode('a')).toBe(-1)
+			expect(enumTag.nameToCode('x')).toBe(-1)
+			expect(enumTag.nameToCode('b')).toBe(10)
+
+			expect(enumTag.codeToName(9)).toBe('b')
+			expect(enumTag.codeToName(10)).toBe('b')
+		})
+
 		it('creates an enum tag from a grid with no codes', () => {
 			const grid = new HGrid([
 				new HDict({

src/core/EnumTag.ts

@@ -65,19 +65,14 @@ export class EnumTag {
 		let falseName: string | undefined
 
 		const addEnumEntry = (name: string, code: number): void => {
-			if (
-				!this.#nameToCodeMap.has(name) &&
-				!this.#codeToNameMap.has(code)
-			) {
-				if (!trueName && code) {
-					trueName = name
-				}
-				if (!falseName && !code) {
-					falseName = name
-				}
-				this.#nameToCodeMap.set(name, code)
-				this.#codeToNameMap.set(code, name)
+			if (!trueName && code) {
+				trueName = name
+			}
+			if (!falseName && !code) {
+				falseName = name
 			}
+			this.#nameToCodeMap.set(name, code)
+			this.#codeToNameMap.set(code, name)
 		}
 
 		if (typeof data === 'string' || valueIsKind<HStr>(data, Kind.Str)) {