From 4f745155087bbb8cd4e0a4da0953d3fa867d1383 Mon Sep 17 00:00:00 2001
From: Mikhail Zarechenskiy <mikhail.zarechenskiy@jetbrains.com>
Date: Thu, 16 Jan 2020 13:34:34 +0300
Subject: [PATCH] [NI] Fix CST calculation for covariant type projections

---
 .../calls/NewCommonSuperTypeCalculator.kt     |  3 ++-
 .../nonFixedVariableFromBothBranches.kt       |  2 +-
 .../elvisOperatorAgainstFlexibleType.kt       | 20 +++++++++++++++++++
 .../elvisOperatorAgainstFlexibleType.txt      | 15 ++++++++++++++
 .../DiagnosticsTestWithStdLibGenerated.java   |  5 +++++
 ...ticsTestWithStdLibUsingJavacGenerated.java |  5 +++++
 6 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.kt
 create mode 100644 compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.txt

diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/NewCommonSuperTypeCalculator.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/NewCommonSuperTypeCalculator.kt
index d0e41539851..1ca3cd7c2d4 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/NewCommonSuperTypeCalculator.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/NewCommonSuperTypeCalculator.kt
@@ -388,7 +388,8 @@ object NewCommonSuperTypeCalculator {
             return if (equalToEachOtherType == null) {
                 createTypeArgument(commonSuperType(argumentTypes, depth + 1), TypeVariance.OUT)
             } else {
-                createTypeArgument(equalToEachOtherType.getType(), TypeVariance.INV)
+                val thereIsNotInv = arguments.any { it.getVariance() != TypeVariance.INV }
+                createTypeArgument(equalToEachOtherType.getType(), if (thereIsNotInv) TypeVariance.OUT else TypeVariance.INV)
             }
         } else {
             val type = intersectTypes(arguments.map { it.getType() })
diff --git a/compiler/testData/diagnostics/tests/inference/commonSystem/nonFixedVariableFromBothBranches.kt b/compiler/testData/diagnostics/tests/inference/commonSystem/nonFixedVariableFromBothBranches.kt
index 03de747369f..3b672bd96c7 100644
--- a/compiler/testData/diagnostics/tests/inference/commonSystem/nonFixedVariableFromBothBranches.kt
+++ b/compiler/testData/diagnostics/tests/inference/commonSystem/nonFixedVariableFromBothBranches.kt
@@ -16,5 +16,5 @@ fun <R> foo(f: () -> R): R = f()
 fun test(n: Number) {
     val a = select(foo { JavaTest.createNumberArray() }, emptyArray())
 
-    <!DEBUG_INFO_EXPRESSION_TYPE("(kotlin.Array<(kotlin.Number..kotlin.Number?)>..kotlin.Array<(kotlin.Number..kotlin.Number?)>?)")!>a<!>
+    <!DEBUG_INFO_EXPRESSION_TYPE("(kotlin.Array<(kotlin.Number..kotlin.Number?)>..kotlin.Array<out (kotlin.Number..kotlin.Number?)>?)")!>a<!>
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.kt b/compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.kt
new file mode 100644
index 00000000000..1c3cd886044
--- /dev/null
+++ b/compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.kt
@@ -0,0 +1,20 @@
+// !LANGUAGE: +NewInference
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+
+// FILE: Foo.java
+
+public class Foo {
+    public static <K, V> void create(java.util.Map<? extends K, ? extends V> m) { return null; }
+}
+
+// FILE: test.kt
+
+fun test(properties: Map<String, String>, nullableProperties: Map<String, String>?) {
+    val f1 = Foo.create(select1(properties, myEmptyMap()))
+    val f2 = Foo.create(nullableProperties ?: myEmptyMap())
+}
+
+fun <T, R> myEmptyMap(): Map<T, R> = TODO()
+
+@Suppress("INVISIBLE_REFERENCE")
+fun <S> select1(x: S, y: S): @kotlin.internal.Exact S = y
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.txt b/compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.txt
new file mode 100644
index 00000000000..35640e14375
--- /dev/null
+++ b/compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.txt
@@ -0,0 +1,15 @@
+package
+
+public fun </*0*/ T, /*1*/ R> myEmptyMap(): kotlin.collections.Map<T, R>
+@kotlin.Suppress(names = {"INVISIBLE_REFERENCE"}) public fun </*0*/ S> select1(/*0*/ x: S, /*1*/ y: S): S
+public fun test(/*0*/ properties: kotlin.collections.Map<kotlin.String, kotlin.String>, /*1*/ nullableProperties: kotlin.collections.Map<kotlin.String, kotlin.String>?): kotlin.Unit
+
+public open class Foo {
+    public constructor Foo()
+    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
+
+    // Static members
+    public open fun </*0*/ K : kotlin.Any!, /*1*/ V : kotlin.Any!> create(/*0*/ m: (kotlin.collections.MutableMap<out K!, out V!>..kotlin.collections.Map<out K!, V!>?)): kotlin.Unit
+}
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithStdLibGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithStdLibGenerated.java
index 5d33b4ed007..c81ef793617 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithStdLibGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithStdLibGenerated.java
@@ -1902,6 +1902,11 @@ public class DiagnosticsTestWithStdLibGenerated extends AbstractDiagnosticsTestW
                 runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/correctMember.kt");
             }
 
+            @TestMetadata("elvisOperatorAgainstFlexibleType.kt")
+            public void testElvisOperatorAgainstFlexibleType() throws Exception {
+                runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.kt");
+            }
+
             @TestMetadata("extensionPriority.kt")
             public void testExtensionPriority() throws Exception {
                 runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/extensionPriority.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsTestWithStdLibUsingJavacGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsTestWithStdLibUsingJavacGenerated.java
index 69a56811d24..4a6da1c3459 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsTestWithStdLibUsingJavacGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsTestWithStdLibUsingJavacGenerated.java
@@ -1902,6 +1902,11 @@ public class DiagnosticsTestWithStdLibUsingJavacGenerated extends AbstractDiagno
                 runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/correctMember.kt");
             }
 
+            @TestMetadata("elvisOperatorAgainstFlexibleType.kt")
+            public void testElvisOperatorAgainstFlexibleType() throws Exception {
+                runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/elvisOperatorAgainstFlexibleType.kt");
+            }
+
             @TestMetadata("extensionPriority.kt")
             public void testExtensionPriority() throws Exception {
                 runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/inference/extensionPriority.kt");