Do not allow optimize imports for uncommitted document

Optimize imports may be called after executing command, and document can be uncommitted after command is finished. In that case we will get ISE: Attempt to modify PSI for non-committed Document

#EA-209693 fixed

idea/src/org/jetbrains/kotlin/idea/imports/KotlinImportOptimizer.kt

@@ -20,6 +20,7 @@ import com.intellij.lang.ImportOptimizer
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.progress.ProgressIndicatorProvider
 import com.intellij.openapi.util.text.StringUtil
+import com.intellij.psi.PsiDocumentManager
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import org.jetbrains.kotlin.descriptors.*
@@ -60,9 +61,23 @@ class KotlinImportOptimizer : ImportOptimizer {
         }
     }
 
+    // The same as com.intellij.pom.core.impl.PomModelImpl.isDocumentUncommitted
+    // Which is checked in com.intellij.pom.core.impl.PomModelImpl.startTransaction
+    private val KtFile.isDocumentUncommitted: Boolean
+        get() {
+            val documentManager = PsiDocumentManager.getInstance(project)
+            val cachedDocument = documentManager.getCachedDocument(this)
+            return cachedDocument != null && documentManager.isUncommited(cachedDocument)
+        }
+
     private fun prepareImports(file: KtFile): OptimizeInformation? {
         ApplicationManager.getApplication().assertReadAccessAllowed()
 
+        // Optimize imports may be called after command
+        // And document can be uncommitted after running that command
+        // In that case we will get ISE: Attempt to modify PSI for non-committed Document!
+        if (file.isDocumentUncommitted) return null
+
         val moduleInfo = file.getNullableModuleInfo()
         if (moduleInfo !is ModuleSourceInfo && moduleInfo !is ScriptModuleInfo) return null