fix(decode): Fix off-by-one error (#858)

Author: fb55

src/decode.spec.ts

@@ -39,4 +39,7 @@ describe("Decode test", () => {
 
     it("should not parse numeric entities in strict mode", () =>
         expect(entities.decodeHTMLStrict("&#55")).toBe("&#55"));
+
+    it("should parse &nbsp followed by < (#852)", () =>
+        expect(entities.decodeHTML("&nbsp<")).toBe("\u00a0<"));
 });

src/decode.ts

@@ -150,7 +150,7 @@ export function determineBranch(
     if (jumpOffset) {
         const value = char - jumpOffset;
 
-        return value < 0 || value > branchCount
+        return value < 0 || value >= branchCount
             ? -1
             : decodeTree[nodeIdx + value] - 1;
     }