From 2e214a45debb01b8ac1bd0b9a4b6e58e6363c18c Mon Sep 17 00:00:00 2001
From: Karcsesz <34425884+karcsesz@users.noreply.github.com>
Date: Sat, 1 Nov 2025 18:43:17 +0100
Subject: [PATCH] Fix minecraft version 1.21.1 pulling in NeoForge versions for
 1.21.10 (#370)

Since the compatibility check only verified that the first characters matched
between the version strings, a one-character patch version could be
misinterpreted if a two-character patch version existed.
---
 core/versionutil.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/core/versionutil.go b/core/versionutil.go
index 31116f3..d9dcd46 100644
--- a/core/versionutil.go
+++ b/core/versionutil.go
@@ -177,7 +177,11 @@ func FetchMavenWithNeoForgeStyleVersions(url string, friendlyName string) func(m
 		if len(mcSplit) > 2 {
 			mcMinor = mcSplit[2]
 		}
-		return strings.HasPrefix(neoforgeVersion, mcMajor+"."+mcMinor)
+
+		// We can only accept an exact version number match, because otherwise 1.21.1 would pull in loader versions for 1.21.10.
+		var requiredPrefix = mcMajor + "." + mcMinor + "."
+
+		return strings.HasPrefix(neoforgeVersion, requiredPrefix)
 	})
 }