KSCM: fix wrong update on null return from Template.getDependenciesFor

Author: PVTalanov

idea/idea-core/src/org/jetbrains/kotlin/idea/core/script/KotlinScriptConfigurationManager.kt

@@ -224,7 +224,7 @@ class KotlinScriptConfigurationManager(
  val currentTimeStamp = TimeStamps.next()
  val scriptContents = scriptDefinition.makeScriptContents(file, project)
  val newFuture = supplyAsync(Supplier {
- val newDependencies = scriptDefinition.getDependenciesFor(oldDataAndRequest?.dependencies, scriptContents)
+ val newDependencies = scriptDefinition.getDependenciesFor(oldDataAndRequest?.dependencies, scriptContents) ?: EmptyDependencies
  cacheLock.read {
  val lastTimeStamp = cache[path]?.requestInProgress?.timeStamp
  if (lastTimeStamp == currentTimeStamp) {
@@ -254,31 +254,27 @@ class KotlinScriptConfigurationManager(
  private fun <TF : Any> updateSync(file: TF, scriptDef: KotlinScriptDefinition): Boolean {
  val path = getFilePath(file)
  val oldDeps = cache[path]?.dependencies
- val deps = scriptDef.getDependenciesFor(file, project, oldDeps)
+ val deps = scriptDef.getDependenciesFor(file, project, oldDeps) ?: EmptyDependencies
  return cacheSync(deps, oldDeps, path, file as? VirtualFile)
  }
 
  private fun cacheSync(
- new: KotlinScriptExternalDependencies?,
+ new: KotlinScriptExternalDependencies,
  old: KotlinScriptExternalDependencies?,
  path: String,
  file: VirtualFile?
  ): Boolean {
  return when {
- new != null && (old == null || !(new.match(old))) -> {
+ old == null || !(new.match(old)) -> {
  // changed or new
  save(path, new, file, persist = true)
  true
  }
- new != null -> {
+ else -> {
  save(path, new, file, persist = false)
+ // same
  false
- } // same
- cache.remove(path) != null -> {
- save(path, null, file, persist = true)
- true
  }
- else -> false // unknown
  }
  }
 
@@ -384,3 +380,5 @@ object TimeStamps {
 
  fun next() = TimeStamp(current++)
 }
+
+private object EmptyDependencies: KotlinScriptExternalDependencies