From 817bdc3b2fcd72a1de648213ad5fe8bdd347127c Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Tue, 4 Jan 2022 19:44:22 -0800
Subject: [PATCH] Prefer type of overridden member when inferring

---
 .../scala/tools/nsc/typechecker/Namers.scala      |  7 ++++---
 test/files/pos/t7212.scala                        | 15 +++++++++++++++
 test/files/pos/t7212b/JavaClient.java             |  6 ++++++
 test/files/pos/t7212b/JavaThing.java              |  4 ++++
 test/files/pos/t7212b/ScalaThing.scala            |  6 ++++++
 5 files changed, 35 insertions(+), 3 deletions(-)
 create mode 100644 test/files/pos/t7212.scala
 create mode 100644 test/files/pos/t7212b/JavaClient.java
 create mode 100644 test/files/pos/t7212b/JavaThing.java
 create mode 100644 test/files/pos/t7212b/ScalaThing.scala

diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index 039281214c00..d31e5ad3d472 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -1126,9 +1126,10 @@ trait Namers extends MethodSynthesis {
         case ddef: DefDef if tree.symbol.isTermMacro => defnTyper.computeMacroDefType(ddef, pt)
         case _ => defnTyper.computeType(tree.rhs, pt)
       }
-
-      val defnTpe = dropIllegalStarTypes(widenIfNecessary(tree.symbol, rhsTpe, pt))
-      tree.tpt defineType defnTpe setPos tree.pos.focus
+      tree.tpt.defineType {
+        if (currentRun.isScala3 && !pt.isWildcard && pt != NoType && !pt.isErroneous) pt
+        else dropIllegalStarTypes(widenIfNecessary(tree.symbol, rhsTpe, pt))
+      }.setPos(tree.pos.focus)
       tree.tpt.tpe
     }
 
diff --git a/test/files/pos/t7212.scala b/test/files/pos/t7212.scala
new file mode 100644
index 000000000000..1c1a3f07a2c2
--- /dev/null
+++ b/test/files/pos/t7212.scala
@@ -0,0 +1,15 @@
+
+// scalac: -Xsource:3
+
+class A {
+  def f: Option[String] = Some("hello, world")
+  def remove(): Unit = ()
+}
+class B extends A {
+  override def f = None
+  override def remove() = ???
+}
+class C extends B {
+  override def f: Option[String] = Some("goodbye, cruel world")
+  override def remove(): Unit = println("removed! (not really)")
+}
diff --git a/test/files/pos/t7212b/JavaClient.java b/test/files/pos/t7212b/JavaClient.java
new file mode 100644
index 000000000000..8fb0650e9bd5
--- /dev/null
+++ b/test/files/pos/t7212b/JavaClient.java
@@ -0,0 +1,6 @@
+
+public class JavaClient extends ScalaThing {
+	public void remove() {
+		throw new UnsupportedOperationException();
+	}
+}
diff --git a/test/files/pos/t7212b/JavaThing.java b/test/files/pos/t7212b/JavaThing.java
new file mode 100644
index 000000000000..4c3f6cab0b47
--- /dev/null
+++ b/test/files/pos/t7212b/JavaThing.java
@@ -0,0 +1,4 @@
+
+public interface JavaThing {
+	default void remove() { throw new UnsupportedOperationException(); }
+}
diff --git a/test/files/pos/t7212b/ScalaThing.scala b/test/files/pos/t7212b/ScalaThing.scala
new file mode 100644
index 000000000000..8416ba633d01
--- /dev/null
+++ b/test/files/pos/t7212b/ScalaThing.scala
@@ -0,0 +1,6 @@
+
+// scalac: -Xsource:3
+
+class ScalaThing extends JavaThing {
+  override def remove() = ???
+}