KotlinLanguageInjector can inject into files modified for autocompletion

idea/idea-jvm/src/org/jetbrains/kotlin/idea/injection/KotlinLanguageInjector.kt

@@ -75,7 +75,7 @@ class KotlinLanguageInjector(
 
         val support = kotlinSupport ?: return
 
-        if (!ProjectRootsUtil.isInProjectOrLibSource(ktHost)) return
+        if (!ProjectRootsUtil.isInProjectOrLibSource(ktHost.containingFile.originalFile)) return
 
         val needImmediateAnswer = with(ApplicationManager.getApplication()) { isDispatchThread && !isUnitTestMode }
         val kotlinCachedInjection = ktHost.cachedInjectionWithModification

idea/tests/org/jetbrains/kotlin/psi/KotlinInjectionTest.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.psi
 
+import com.intellij.codeInsight.completion.CompletionType
 import com.intellij.lang.html.HTMLLanguage
 import com.intellij.openapi.fileTypes.PlainTextLanguage
 import org.intellij.lang.regexp.RegExpLanguage
@@ -513,6 +514,9 @@ class KotlinInjectionTest : AbstractInjectionTest() {
                     HTMLLanguage.INSTANCE.id,
                     unInjectShouldBePresent = false
             )
+
+            assertSameElements(myFixture.complete(CompletionType.BASIC).flatMap { it.allLookupStrings },
+                               "html")
         }
         finally {
             Configuration.getInstance().replaceInjections(listOf(), listOf(customInjection), true)