From e0e3400ef85aa7dc6f565ef2f1662a66fbb6b7d0 Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Fri, 8 Jul 2022 11:50:59 +0200
Subject: [PATCH 1/2] Don't check import selectors for Java code

Moving import selector checking from PostTyper to Typer had the
side-effect that they were also checked in Java code. But that does
not work since the Java files are compiled before the Scala files
so the selected reference has not been seen yet.

Fixed by disabling import selector checks for Java files.

Fixes #15608
---
 .../src/dotty/tools/dotc/typer/Checking.scala |  5 +++--
 tests/pos/i15608/JavaMDCBinder.java           | 20 +++++++++++++++++++
 tests/pos/i15608/Test.scala                   |  6 ++++++
 3 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 tests/pos/i15608/JavaMDCBinder.java
 create mode 100644 tests/pos/i15608/Test.scala

diff --git a/compiler/src/dotty/tools/dotc/typer/Checking.scala b/compiler/src/dotty/tools/dotc/typer/Checking.scala
index 5a540f108420..bc9e22b8e4ed 100644
--- a/compiler/src/dotty/tools/dotc/typer/Checking.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Checking.scala
@@ -1460,8 +1460,9 @@ trait Checking {
         report.error(ImportRenamedTwice(sel.imported), sel.imported.srcPos)
       seen += sel.name
 
-    for sel <- selectors do
-      if !sel.isWildcard then checkIdent(sel)
+    if !ctx.compilationUnit.isJava then
+      for sel <- selectors do
+        if !sel.isWildcard then checkIdent(sel)
   end checkImportSelectors
 }
 
diff --git a/tests/pos/i15608/JavaMDCBinder.java b/tests/pos/i15608/JavaMDCBinder.java
new file mode 100644
index 000000000000..d7ac2270e154
--- /dev/null
+++ b/tests/pos/i15608/JavaMDCBinder.java
@@ -0,0 +1,20 @@
+package foo.slf4j.impl;
+
+import bar.slf4j.MDCAdapter;
+import bar.slf4j.ScalaMDCAdapter;
+import bar.slf4j.ScalaMDCAdapter$;
+
+public class JavaMDCBinder {
+    public static final JavaMDCBinder SINGLETON = new JavaMDCBinder();
+
+    private JavaMDCBinder() {
+    }
+
+    public MDCAdapter getMDCA() {
+        return ScalaMDCAdapter$.MODULE$;
+    }
+
+    public String getMDCAdapterClassStr() {
+        return ScalaMDCAdapter.class.getName();
+    }
+}
\ No newline at end of file
diff --git a/tests/pos/i15608/Test.scala b/tests/pos/i15608/Test.scala
new file mode 100644
index 000000000000..d357bfcd4c5c
--- /dev/null
+++ b/tests/pos/i15608/Test.scala
@@ -0,0 +1,6 @@
+package bar.slf4j
+
+trait MDCAdapter
+
+object ScalaMDCAdapter extends MDCAdapter {
+}

From 747fa5c88798ae60c252dc7ced3efebf1311aae3 Mon Sep 17 00:00:00 2001
From: odersky <odersky@gmail.com>
Date: Fri, 8 Jul 2022 13:48:24 +0200
Subject: [PATCH 2/2] Fix test

---
 tests/pos/i15608/{ => bar}/Test.scala         | 2 +-
 tests/pos/i15608/{ => foo}/JavaMDCBinder.java | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)
 rename tests/pos/i15608/{ => bar}/Test.scala (78%)
 rename tests/pos/i15608/{ => foo}/JavaMDCBinder.java (72%)

diff --git a/tests/pos/i15608/Test.scala b/tests/pos/i15608/bar/Test.scala
similarity index 78%
rename from tests/pos/i15608/Test.scala
rename to tests/pos/i15608/bar/Test.scala
index d357bfcd4c5c..01366d02d080 100644
--- a/tests/pos/i15608/Test.scala
+++ b/tests/pos/i15608/bar/Test.scala
@@ -1,4 +1,4 @@
-package bar.slf4j
+package bar
 
 trait MDCAdapter
 
diff --git a/tests/pos/i15608/JavaMDCBinder.java b/tests/pos/i15608/foo/JavaMDCBinder.java
similarity index 72%
rename from tests/pos/i15608/JavaMDCBinder.java
rename to tests/pos/i15608/foo/JavaMDCBinder.java
index d7ac2270e154..58670339278e 100644
--- a/tests/pos/i15608/JavaMDCBinder.java
+++ b/tests/pos/i15608/foo/JavaMDCBinder.java
@@ -1,8 +1,8 @@
-package foo.slf4j.impl;
+package foo;
 
-import bar.slf4j.MDCAdapter;
-import bar.slf4j.ScalaMDCAdapter;
-import bar.slf4j.ScalaMDCAdapter$;
+import bar.MDCAdapter;
+import bar.ScalaMDCAdapter;
+import bar.ScalaMDCAdapter$;
 
 public class JavaMDCBinder {
     public static final JavaMDCBinder SINGLETON = new JavaMDCBinder();