build.gradle.kts: save gradle project roots per project

Otherwise they can be overwritten if multiple projects are open
Also do not overwrite them in KotlinDslScrtiptModelProcessor because it can be called multiple times during import

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/GradleScriptInputsWatcher.kt

@@ -6,9 +6,12 @@
 package org.jetbrains.kotlin.idea.scripting.gradle
 
 import com.intellij.openapi.components.*
+import com.intellij.openapi.externalSystem.util.ExternalSystemApiUtil
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.vfs.VirtualFile
 import org.jetbrains.annotations.TestOnly
+import org.jetbrains.plugins.gradle.settings.GradleProjectSettings
+import org.jetbrains.plugins.gradle.util.GradleConstants
 
 @State(
     name = "KotlinBuildScriptsModificationInfo",
@@ -17,6 +20,34 @@ import org.jetbrains.annotations.TestOnly
 class GradleScriptInputsWatcher(val project: Project) : PersistentStateComponent<GradleScriptInputsWatcher.Storage> {
     private var storage = Storage()
 
+    private var cachedGradleProjectsRoots: Set<String>? = null
+
+    fun getGradleProjectsRoots(): Set<String> {
+        if (cachedGradleProjectsRoots == null) {
+            cachedGradleProjectsRoots = computeGradleProjectRoots(project)
+        }
+        return cachedGradleProjectsRoots ?: emptySet()
+    }
+
+    fun saveGradleProjectRootsAfterImport(roots: Set<String>) {
+        val oldRoots = cachedGradleProjectsRoots
+        if (oldRoots != null && oldRoots.isNotEmpty()) {
+            cachedGradleProjectsRoots = oldRoots + roots
+        } else {
+            cachedGradleProjectsRoots = roots
+        }
+    }
+
+    private fun computeGradleProjectRoots(project: Project): Set<String> {
+        val gradleSettings = ExternalSystemApiUtil.getSettings(project, GradleConstants.SYSTEM_ID)
+        if (gradleSettings.getLinkedProjectsSettings().isEmpty()) return setOf()
+
+        val projectSettings = gradleSettings.getLinkedProjectsSettings().filterIsInstance<GradleProjectSettings>().firstOrNull()
+            ?: return setOf()
+
+        return projectSettings.modules.takeIf { it.isNotEmpty() } ?: setOf(projectSettings.externalProjectPath)
+    }
+
     fun startWatching() {
         addVfsListener(this)
     }

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/importing/KotlinDslScrtiptModelProcessor.kt

@@ -13,7 +13,6 @@ import org.jetbrains.kotlin.idea.core.script.configuration.cache.CachedConfigura
 import org.jetbrains.kotlin.idea.core.script.configuration.cache.ScriptConfigurationSnapshot
 import org.jetbrains.kotlin.idea.scripting.gradle.GradleScriptInputsWatcher
 import org.jetbrains.kotlin.idea.scripting.gradle.getGradleScriptInputsStamp
-import org.jetbrains.kotlin.idea.scripting.gradle.saveGradleProjectRootsAfterImport
 import org.jetbrains.kotlin.scripting.definitions.findScriptDefinition
 import org.jetbrains.kotlin.scripting.resolve.ScriptCompilationConfigurationWrapper
 import org.jetbrains.kotlin.scripting.resolve.VirtualFileScriptSource
@@ -86,7 +85,7 @@ fun saveScriptModels(
         errorReporter.reportError(scriptFile, model)
     }
 
-    saveGradleProjectRootsAfterImport(
+    project.service<GradleScriptInputsWatcher>().saveGradleProjectRootsAfterImport(
         scriptConfigurations.map { it.first.parent.path }.toSet()
     )
 

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/utils.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.idea.scripting.gradle
 
 import com.intellij.openapi.application.ApplicationManager
+import com.intellij.openapi.components.service
 import com.intellij.openapi.externalSystem.util.ExternalSystemApiUtil
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.registry.Registry
@@ -34,35 +35,12 @@ fun isInAffectedGradleProjectFiles(project: Project, filePath: String): Boolean
             return true
         }
 
-        return filePath.substringBeforeLast("/") in getGradleProjectsRoots(project)
+        return filePath.substringBeforeLast("/") in project.service<GradleScriptInputsWatcher>().getGradleProjectsRoots()
     }
 
     return false
 }
 
-private var cachedGradleProjectsRoots: Set<String>? = null
-
-private fun getGradleProjectsRoots(project: Project): Set<String> {
-    if (cachedGradleProjectsRoots == null) {
-        cachedGradleProjectsRoots = computeGradleProjectRoots(project)
-    }
-    return cachedGradleProjectsRoots ?: emptySet()
-}
-
-fun saveGradleProjectRootsAfterImport(roots: Set<String>) {
-    cachedGradleProjectsRoots = roots
-}
-
-private fun computeGradleProjectRoots(project: Project): Set<String> {
-    val gradleSettings = ExternalSystemApiUtil.getSettings(project, GradleConstants.SYSTEM_ID)
-    if (gradleSettings.getLinkedProjectsSettings().isEmpty()) return setOf()
-
-    val projectSettings = gradleSettings.getLinkedProjectsSettings().filterIsInstance<GradleProjectSettings>().firstOrNull()
-        ?: return setOf()
-
-    return projectSettings.modules.takeIf { it.isNotEmpty() } ?: setOf(projectSettings.externalProjectPath)
-}
-
 fun getGradleScriptInputsStamp(
     project: Project,
     file: VirtualFile,