Fix existing OptiFine install for MultiMC

Fixes #107
ImpactDevelopment · Aug 16, 2020 · 1020bbf · 1020bbf
1 parent 75d8515
commit 1020bbf
Show file tree

Hide file tree

Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixes
+- Fix using an already installed OptiFine version not working correctly for MultiMC instances ([#107](https://github.com/ImpactDevelopment/Installer/issues/107))
+
 ## [0.9.2] - 2020-08-09
 
 ### Fixes

diff --git a/src/main/java/io/github/ImpactDevelopment/installer/optifine/OptiFineExisting.java b/src/main/java/io/github/ImpactDevelopment/installer/optifine/OptiFineExisting.java
@@ -41,7 +41,11 @@ public OptiFineExisting(Path libraries, String version) throws RuntimeException
 
     @Override
     protected void installOptiFine(Path destination, Path vanilla) throws IOException, InvocationTargetException, IllegalAccessException {
-        // No-op: this class was built from the installed OptiFine, "installing" it over itself is paradoxical
+        // This class was built from the installed OptiFine, so normally the destination _is_ the installer jar, however
+        // that isn't guaranteed, e.g. the installed jar could be used to install optiFine into a new MultiMC instance.
+        if (!Files.exists(destination)) {
+            super.installOptiFine(destination, vanilla);
+        }
     }
 
     @Override