Functions returning Nothing are indexed even when alias import is used

idea/ide-common/src/org/jetbrains/kotlin/util/TypeIndexUtil.kt

@@ -18,12 +18,20 @@ package org.jetbrains.kotlin.util
 
 import com.google.common.collect.HashMultimap
 import com.google.common.collect.Multimap
+import com.google.common.collect.Multimaps
 import com.intellij.openapi.util.Key
 import org.jetbrains.kotlin.psi.JetFile
 import org.jetbrains.kotlin.psi.JetTypeReference
 import org.jetbrains.kotlin.psi.JetUserType
+import org.jetbrains.kotlin.psi.stubs.getContainingFileStub
 
-public fun JetFile.aliasImportMap(): Multimap<String, String> {
+public fun JetUserType.aliasImportMap(): Multimap<String, String> {
+    // we need to access containing file via stub because getPsi() may return null when indexing and getContainingFile() will crash
+    val file = getStub()?.getContainingFileStub()?.getPsi() ?: return HashMultimap.create()
+    return (file as JetFile).aliasImportMap()
+}
+
+private fun JetFile.aliasImportMap(): Multimap<String, String> {
     val cached = getUserData(ALIAS_IMPORT_DATA_KEY)
     val modificationStamp = getModificationStamp()
     if (cached != null && modificationStamp == cached.fileModificationStamp) {
@@ -55,6 +63,9 @@ public fun JetTypeReference?.isProbablyNothing(): Boolean {
     return userType.isProbablyNothing()
 }
 
-public fun JetUserType?.isProbablyNothing(): Boolean
-        = this?.getReferencedName() == "Nothing"
+public fun JetUserType?.isProbablyNothing(): Boolean {
+    if (this == null) return false
+    val referencedName = getReferencedName()
+    return referencedName == "Nothing" || aliasImportMap()[referencedName].contains("Nothing")
+}
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/IndexUtils.kt

@@ -28,11 +28,11 @@ import org.jetbrains.kotlin.util.aliasImportMap
 fun indexTopLevelExtension<TDeclaration : JetCallableDeclaration>(stub: KotlinCallableStubBase<TDeclaration>, sink: IndexSink) {
     if (stub.isExtension()) {
         val declaration = stub.getPsi()
-        declaration.getReceiverTypeReference()!!.getTypeElement()?.index(declaration, stub.getContainingFileStub().getPsi() != null, sink)
+        declaration.getReceiverTypeReference()!!.getTypeElement()?.index(declaration, sink)
     }
 }
 
-private fun <TDeclaration : JetCallableDeclaration> JetTypeElement.index(declaration: TDeclaration, hasFile: Boolean, sink: IndexSink) {
+private fun <TDeclaration : JetCallableDeclaration> JetTypeElement.index(declaration: TDeclaration, sink: IndexSink) {
     fun occurrence(typeName: String) {
         val name = declaration.getName() ?: return
         sink.occurrence(JetTopLevelExtensionsByReceiverTypeIndex.INSTANCE.getKey(),
@@ -48,7 +48,7 @@ private fun <TDeclaration : JetCallableDeclaration> JetTypeElement.index(declara
                 if (typeParameter != null) {
                     val bound = typeParameter.getExtendsBound()
                     if (bound != null) {
-                        bound.getTypeElement()?.index(declaration, hasFile, sink)
+                        bound.getTypeElement()?.index(declaration, sink)
                         return
                     }
                     occurrence("Any")
@@ -58,13 +58,10 @@ private fun <TDeclaration : JetCallableDeclaration> JetTypeElement.index(declara
 
             occurrence(referenceName)
 
-            if (hasFile) {
-                val aliasNames = declaration.getContainingJetFile().aliasImportMap()[referenceName]
-                aliasNames.forEach { occurrence(it) }
-            }
+            aliasImportMap()[referenceName].forEach { occurrence(it) }
         }
 
-        is JetNullableType -> getInnerType()?.index(declaration, hasFile, sink)
+        is JetNullableType -> getInnerType()?.index(declaration, sink)
 
         is JetFunctionType -> {
             val typeName = (if (getReceiverTypeReference() != null) "ExtensionFunction" else "Function") + getParameters().size()

idea/testData/resolve/partialBodyResolve/IfNotIsMyErrorWithAliasImport.dump

@@ -0,0 +1,12 @@
+Resolve target: value-parameter val p: kotlin.Any smart-cast to kotlin.String
+----------------------------------------------
+import kotlin.Nothing as MyNothing
+
+fun myNothingFun(): MyNothing = throw Exception()
+
+fun foo(p: Any) {
+    if (p !is String) {
+        myNothingFun()
+    }
+    println(<caret>p.length())
+}

idea/testData/resolve/partialBodyResolve/IfNotIsMyErrorWithAliasImport.kt

@@ -0,0 +1,10 @@
+import kotlin.Nothing as MyNothing
+
+fun myNothingFun(): MyNothing = throw Exception()
+
+fun foo(p: Any) {
+    if (p !is String) {
+        myNothingFun()
+    }
+    println(<caret>p.length())
+}

idea/tests/org/jetbrains/kotlin/completion/MultiFileJvmBasicCompletionTestGenerated.java

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.completion;
 
 import com.intellij.testFramework.TestDataPath;
+import org.jetbrains.kotlin.test.InnerTestClasses;
 import org.jetbrains.kotlin.test.JUnit3RunnerWithInners;
 import org.jetbrains.kotlin.test.JetTestUtils;
 import org.jetbrains.kotlin.test.TestMetadata;

idea/tests/org/jetbrains/kotlin/idea/resolve/PartialBodyResolveTestGenerated.java

@@ -174,6 +174,12 @@ public class PartialBodyResolveTestGenerated extends AbstractPartialBodyResolveT
         doTest(fileName);
     }
 
+    @TestMetadata("IfNotIsMyErrorWithAliasImport.kt")
+    public void testIfNotIsMyErrorWithAliasImport() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/testData/resolve/partialBodyResolve/IfNotIsMyErrorWithAliasImport.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("IfNotIsNothingProp.kt")
     public void testIfNotIsNothingProp() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/testData/resolve/partialBodyResolve/IfNotIsNothingProp.kt");