Fix ConcurrentModificationException when plugins unload

api/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>samurai</artifactId>
         <groupId>ninja.nonemu</groupId>
-        <version>1.2</version>
+        <version>1.2.1</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>ninja.nonemu</groupId>
     <artifactId>samurai</artifactId>
-    <version>1.2</version>
+    <version>1.2.1</version>
     <modules>
         <module>api</module>
         <module>runtime</module>

runtime/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <artifactId>samurai</artifactId>
         <groupId>ninja.nonemu</groupId>
-        <version>1.2</version>
+        <version>1.2.1</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 

runtime/src/main/java/ninja/nonemu/samurai/plugin/PluginManagerImpl.java

@@ -95,13 +95,16 @@ public class PluginManagerImpl implements PluginManager {
     public void cleanup() {
         logger.trace("Cleaning up plugin manager");
 
-        plugins.keySet().iterator().forEachRemaining((name) -> {
+        String[] pluginNames = new String[plugins.size()];
+        plugins.keySet().toArray(pluginNames);
+
+        for (String pluginName : pluginNames) {
             try {
-                unregisterPlugin(name);
+                unregisterPlugin(pluginName);
             } catch (Exception e) {
                 logger.error("Plugin threw an exception while cleaning up", e);
             }
-        });
+        }
     }
 
     @Override