From 0d393e3fd70b13654b52c1f4ca53674005651d64 Mon Sep 17 00:00:00 2001
From: Pavel Kirpichenkov <pavel.kirpichenkov@jetbrains.com>
Date: Wed, 15 Jan 2020 17:01:44 +0300
Subject: [PATCH] [NI] Update filtering of constraints with equal types

Make check for synthetic nullability constraint status before skipping
new constraint with nonunique type.
---
 .../inference/model/MutableConstraintStorage.kt   |  6 +++++-
 ...ughInformationFromNullabilityConstraint.fir.kt | 15 +++++++++++----
 ...tEnoughInformationFromNullabilityConstraint.kt | 15 +++++++++++----
 ...EnoughInformationFromNullabilityConstraint.txt |  5 ++---
 4 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt
index d9418ab1cc2..5e65ed3b553 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt
@@ -49,7 +49,11 @@ class MutableVariableWithConstraints(
 
     // return new actual constraint, if this constraint is new
     fun addConstraint(constraint: Constraint): Constraint? {
-        val previousConstraintWithSameType = constraints.filter { it.typeHashCode == constraint.typeHashCode && it.type == constraint.type }
+        val previousConstraintWithSameType = constraints.filter { oldConstraint ->
+            oldConstraint.typeHashCode == constraint.typeHashCode
+                    && oldConstraint.type == constraint.type
+                    && oldConstraint.isNullabilityConstraint == constraint.isNullabilityConstraint
+        }
 
         if (previousConstraintWithSameType.any { previous -> newConstraintIsUseless(previous, constraint) })
             return null
diff --git a/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.fir.kt b/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.fir.kt
index d94e0698397..deb087ffcfd 100644
--- a/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.fir.kt
+++ b/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.fir.kt
@@ -1,9 +1,16 @@
-// !LANGUAGE: +NewInference
 // !WITH_NEW_INFERENCE
+// !DIAGNOSTICS: -UNUSED_PARAMETER
 
 fun <M> make(): M? = null
 fun <I> id(arg: I): I = arg
+fun <S> select(vararg args: S): S = TODO()
 
-val v = id(
-    make()
-)
+fun test() {
+    id(
+        make()
+    )
+
+    select(make(), null)
+
+    if (true) make() else TODO()
+}
diff --git a/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.kt b/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.kt
index 941922ee636..d3623a6b6a3 100644
--- a/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.kt
+++ b/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.kt
@@ -1,9 +1,16 @@
-// !LANGUAGE: +NewInference
 // !WITH_NEW_INFERENCE
+// !DIAGNOSTICS: -UNUSED_PARAMETER
 
 fun <M> make(): M? = null
 fun <I> id(arg: I): I = arg
+fun <S> select(vararg args: S): S = TODO()
 
-val v = <!NI;NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER, OI;TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>id<!>(
-    <!NI;NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER, OI;TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>make<!>()
-)
+fun test() {
+    <!NI;NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER, OI;TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>id<!>(
+        <!NI;NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER, OI;TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>make<!>()
+    )
+
+    select(make(), null)
+
+    <!OI;TYPE_INFERENCE_FAILED_ON_SPECIAL_CONSTRUCT!>if<!> (true) <!OI;TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH!>make()<!> else TODO()
+}
diff --git a/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.txt b/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.txt
index ebe772bedaf..390ba5a85d4 100644
--- a/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.txt
+++ b/compiler/testData/diagnostics/tests/inference/nothingType/notEnoughInformationFromNullabilityConstraint.txt
@@ -1,7 +1,6 @@
 package
 
-public val v: [ERROR : Type for id(
-    make()
-)]
 public fun </*0*/ I> id(/*0*/ arg: I): I
 public fun </*0*/ M> make(): M?
+public fun </*0*/ S> select(/*0*/ vararg args: S /*kotlin.Array<out S>*/): S
+public fun test(): kotlin.Unit