From d2c1cbf2a51de07edebbb2b4e3a72abf2e6880e0 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 22 Mar 2026 17:22:08 +0000
Subject: [PATCH] Fix Json.ParseJson crash on empty/null input

ParseJson now returns null for null, empty, or whitespace-only input
instead of throwing JsonReaderException. This matches the behavior of
the old hand-rolled parser and is needed because MC protocol packets
may contain empty strings where JSON text is expected (e.g. empty chat
messages in DeathCombatEvent packets).

Discovered during end-to-end testing against a Minecraft 1.21.11
protocol server.

Co-authored-by: milutinke <441903+milutinke@users.noreply.github.com>
Agent-Logs-Url: https://github.com/milutinke/Minecraft-Console-Client/sessions/34df723e-4a63-45a0-a942-e119d81a575b
---
 MinecraftClient/Json.cs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/MinecraftClient/Json.cs b/MinecraftClient/Json.cs
index c16ca4ea..827a23f4 100644
--- a/MinecraftClient/Json.cs
+++ b/MinecraftClient/Json.cs
@@ -16,8 +16,10 @@ public static class Json
 
     /// <summary>
     /// Parse a JSON string into a mutable <see cref="JsonNode"/> DOM.
+    /// Returns null for null, empty, or whitespace-only input.
     /// </summary>
-    public static JsonNode? ParseJson(string json) => JsonNode.Parse(json);
+    public static JsonNode? ParseJson(string? json) =>
+        string.IsNullOrWhiteSpace(json) ? null : JsonNode.Parse(json);
 
     /// <summary>
     /// Escape a string for embedding inside a JSON string literal.