Fix project leak through child test case disposable

idea/idea-gradle/tests/org/jetbrains/kotlin/gradle/GradleMultiplatformHighlightingTest.kt

@@ -11,6 +11,7 @@ import com.intellij.codeInsight.daemon.DaemonCodeAnalyzer
 import com.intellij.codeInsight.daemon.impl.DaemonCodeAnalyzerImpl
 import com.intellij.codeInsight.daemon.impl.HighlightInfo
 import com.intellij.lang.annotation.HighlightSeverity
+import com.intellij.openapi.Disposable
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.editor.impl.EditorImpl
@@ -55,7 +56,12 @@ class GradleMultiplatformHighlightingTest : GradleImportingTestCase() {
         checkFiles(
             files.filter { it.extension == "kt" },
             project,
-            object : GradleDaemonAnalyzerTestCase(testLineMarkers = true, checkWarnings = true, checkInfos = false) {}
+            object : GradleDaemonAnalyzerTestCase(
+                testLineMarkers = true,
+                checkWarnings = true,
+                checkInfos = false,
+                rootDisposable = testRootDisposable
+            ) {}
         )
     }
 
@@ -67,17 +73,22 @@ class GradleMultiplatformHighlightingTest : GradleImportingTestCase() {
 abstract class GradleDaemonAnalyzerTestCase(
     val testLineMarkers: Boolean,
     val checkWarnings: Boolean,
-    val checkInfos: Boolean
+    val checkInfos: Boolean,
+    private val rootDisposable: Disposable
 ) : DaemonAnalyzerTestCase() {
     override fun doTestLineMarkers() = testLineMarkers
 
     fun checkHighlighting(project: Project, editor: Editor) {
         myProject = project
+        try {
             runInEdtAndWait {
                 // This will prepare ExpectedHighlightingData, clear current editor from testing tags, and then
                 // call doCheckResult, which we override
                 checkHighlighting(editor, checkWarnings, checkInfos)
             }
+        } finally {
+            myProject = null
+        }
     }
 
     // We have to override doCheckResult because one from DaemonAnalyzerTestCase has few flaws:
@@ -117,6 +128,10 @@ abstract class GradleDaemonAnalyzerTestCase(
     protected open fun performAdditionalChecksAfterHighlighting(editor: Editor) { }
 
     protected open fun renderAdditionalAttributeForTag(tag: TagInfo<*>): String? = null
+
+    override fun getTestRootDisposable(): Disposable {
+        return rootDisposable;
+    }
 }
 
 internal fun checkFiles(

idea/idea-gradle/tests/org/jetbrains/kotlin/gradle/ImportAndCheckHighlighting.kt

@@ -34,7 +34,8 @@ class ImportAndCheckHighlighting : MultiplePluginVersionGradleImportingTestCase(
             object : GradleDaemonAnalyzerTestCase(
                 testLineMarkers = testLineMarkers,
                 checkWarnings = checkWarnings,
-                checkInfos = false
+                checkInfos = false,
+                rootDisposable = testRootDisposable
             ) {}
         )
     }

idea/idea-gradle/tests/org/jetbrains/kotlin/idea/codeInsight/gradle/GradleTestRunConfigurationAndHighlightingTest.kt

@@ -49,7 +49,12 @@ class GradleTestRunConfigurationAndHighlightingTest : GradleImportingTestCase()
         checkFiles(
             files.filter { it.extension == "kt" },
             project,
-            object : GradleDaemonAnalyzerTestCase(testLineMarkers = true, checkWarnings = true, checkInfos = false) {
+            object : GradleDaemonAnalyzerTestCase(
+                testLineMarkers = true,
+                checkWarnings = true,
+                checkInfos = false,
+                rootDisposable = testRootDisposable
+            ) {
                 override fun renderAdditionalAttributeForTag(tag: TagsTestDataUtil.TagInfo<*>): String? {
                     val lineMarkerInfo = tag.data as? LineMarkerInfo<*> ?: return null