Scripting: refactor processing of JvmDependencyFromClassLoader in repl

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/impl/KJvmReplCompilerBase.kt

@@ -96,6 +96,9 @@ open class KJvmReplCompilerBase<AnalyzerT : ReplCodeAnalyzerBase>(
 
                 if (messageCollector.hasErrors()) return failure(messageCollector)
 
+                // TODO: support case then JvmDependencyFromClassLoader is registered in non-first line
+                // registerPackageFragmentProvidersIfNeeded already tries to avoid duplicated registering, but impact on
+                // executing it on every snippet needs to be evaluated first
                 if (state.history.isEmpty()) {
                     val updatedConfiguration = ScriptDependenciesProvider.getInstance(context.environment.project)
                         ?.getScriptConfiguration(snippetKtFile)?.configuration

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/impl/ScriptJvmCompilerImpls.kt

@@ -159,9 +159,17 @@ internal fun registerPackageFragmentProvidersIfNeeded(
     scriptCompilationConfiguration: ScriptCompilationConfiguration,
     environment: KotlinCoreEnvironment
 ) {
-    scriptCompilationConfiguration[ScriptCompilationConfiguration.dependencies]?.forEach { dependency ->
+    val scriptDependencies = scriptCompilationConfiguration[ScriptCompilationConfiguration.dependencies] ?: return
-        if (dependency is JvmDependencyFromClassLoader) {
+    val scriptDependenciesFromClassLoader = scriptDependencies.filterIsInstance<JvmDependencyFromClassLoader>().takeIf { it.isNotEmpty() }
-            // TODO: consider implementing deduplication
+        ?: return
+    // TODO: consider implementing deduplication/diff processing
+    val alreadyRegistered =
+        environment.project.extensionArea.getExtensionPoint(PackageFragmentProviderExtension.extensionPointName).extensions.any {
+            (it is PackageFragmentFromClassLoaderProviderExtension) &&
+                    it.scriptCompilationConfiguration[ScriptCompilationConfiguration.dependencies] == scriptDependencies
+        }
+    if (!alreadyRegistered) {
+        scriptDependenciesFromClassLoader.forEach { dependency ->
             PackageFragmentProviderExtension.registerExtension(
                 environment.project,
                 PackageFragmentFromClassLoaderProviderExtension(