Combined identifier info for things like '(x + y).z' is no longer treated as 'z' identifier info + a pair of tests + code fix #KT-9126 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DataFlowValueFactory.java

@@ -26,7 +26,6 @@ import org.jetbrains.kotlin.descriptors.impl.LocalVariableDescriptor;
 import org.jetbrains.kotlin.lexer.JetTokens;
 import org.jetbrains.kotlin.psi.*;
 import org.jetbrains.kotlin.resolve.BindingContext;
-import org.jetbrains.kotlin.resolve.BindingContextUtils;
 import org.jetbrains.kotlin.resolve.DescriptorUtils;
 import org.jetbrains.kotlin.resolve.calls.callUtil.CallUtilPackage;
 import org.jetbrains.kotlin.resolve.calls.context.ResolutionContext;
@@ -188,16 +187,16 @@ public class DataFlowValueFactory {
     }
 
     @NotNull
-    private static IdentifierInfo createPackageInfo(Object id) {
+    private static IdentifierInfo createPackageOrClassInfo(Object id) {
         return new IdentifierInfo(id, true, false, true);
     }
 
     @NotNull
     private static IdentifierInfo combineInfo(@Nullable IdentifierInfo receiverInfo, @NotNull IdentifierInfo selectorInfo) {
-        if (selectorInfo.id == null) {
+        if (selectorInfo.id == null || receiverInfo == NO_IDENTIFIER_INFO) {
             return NO_IDENTIFIER_INFO;
         }
-        if (receiverInfo == null || receiverInfo == NO_IDENTIFIER_INFO || receiverInfo.isPackage) {
+        if (receiverInfo == null || receiverInfo.isPackage) {
             return selectorInfo;
         }
         return createInfo(Pair.create(receiverInfo.id, selectorInfo.id),
@@ -281,8 +280,8 @@ public class DataFlowValueFactory {
                                                         isStableVariable(variableDescriptor, usageModuleDescriptor),
                                                         isUncapturedLocalVariable(variableDescriptor, bindingContext)));
         }
-        if (declarationDescriptor instanceof PackageViewDescriptor) {
-            return createPackageInfo(declarationDescriptor);
+        if (declarationDescriptor instanceof PackageViewDescriptor || declarationDescriptor instanceof ClassDescriptor) {
+            return createPackageOrClassInfo(declarationDescriptor);
         }
         return NO_IDENTIFIER_INFO;
     }

compiler/testData/diagnostics/tests/smartCasts/fieldExclExcl.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS: -UNNECESSARY_NOT_NULL_ASSERTION
+// See KT-9126: Variable change does not affect data flow info for its fields
+
+class My(val x: Int?)
+
+fun foo() {
+    var y: My? = My(42)
+    if (y!!.x != null) {
+        y = My(null)
+        y!!.x<!UNSAFE_CALL!>.<!>hashCode()
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/fieldExclExcl.txt

@@ -0,0 +1,11 @@
+package
+
+public fun foo(): kotlin.Unit
+
+public final class My {
+    public constructor My(/*0*/ x: kotlin.Int?)
+    public final val x: kotlin.Int?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/smartCasts/fieldPlus.kt

@@ -0,0 +1,14 @@
+// !DIAGNOSTICS: -UNNECESSARY_NOT_NULL_ASSERTION
+// Advancement of KT-9126
+
+class My(val x: Int?) {
+    fun plus(y: My) = if (this.x != null) this else y
+}
+
+fun foo() {
+    var y: My? = My(42)
+    if (y!!.x != null) {
+        y = My(null)
+        (<!DEBUG_INFO_SMARTCAST!>y<!> + My(0)).x<!UNSAFE_CALL!>.<!>hashCode()
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/fieldPlus.txt

@@ -0,0 +1,12 @@
+package
+
+public fun foo(): kotlin.Unit
+
+public final class My {
+    public constructor My(/*0*/ x: kotlin.Int?)
+    public final val x: kotlin.Int?
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final fun plus(/*0*/ y: My): My
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java

@@ -13197,6 +13197,18 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("fieldExclExcl.kt")
+            public void testFieldExclExcl() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/smartCasts/fieldExclExcl.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("fieldPlus.kt")
+            public void testFieldPlus() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/smartCasts/fieldPlus.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("kt1461.kt")
             public void testKt1461() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/smartCasts/kt1461.kt");

idea/src/org/jetbrains/kotlin/idea/actions/JavaToKotlinAction.kt

@@ -73,7 +73,7 @@ public class JavaToKotlinAction : AnAction() {
                 ProgressManager.getInstance().runProcessWithProgressSynchronously(
                         {
                             runReadAction {
-                                externalCodeUpdate = converterResult!!.externalCodeProcessing.prepareWriteOperation(ProgressManager.getInstance().getProgressIndicator())
+                                externalCodeUpdate = converterResult!!.externalCodeProcessing!!.prepareWriteOperation(ProgressManager.getInstance().getProgressIndicator())
                             }
                         },
                         title,