do not look in companion in javaFindMember in typedSelect

Author: bishabosha

compiler/src/dotty/tools/dotc/core/ContextOps.scala

@@ -34,7 +34,10 @@ object ContextOps:
               if (elem.name == name) return elem.sym.denot // return self
             }
             val pre = ctx.owner.thisType
-            if ctx.isJava then javaFindMember(name, pre, required, excluded)
+            if ctx.isJava then
+              // Note: I didn't verify if there exists a code path that would require `lookInCompanion = true`,
+              // it is just to preserve the original behavior.
+              javaFindMember(name, pre, lookInCompanion = true, required, excluded)
             else pre.findMember(name, pre, required, excluded)
           }
           else // we are in the outermost context belonging to a class; self is invisible here. See inClassContext.
@@ -43,7 +46,13 @@ object ContextOps:
           ctx.scope.denotsNamed(name).filterWithFlags(required, excluded).toDenot(NoPrefix)
       }
 
-    final def javaFindMember(name: Name, pre: Type, required: FlagSet = EmptyFlags, excluded: FlagSet = EmptyFlags): Denotation =
+    /** Look in the prefix with Java semantics.
+     * @param lookInCompanion  If true, try in the companion class of a module as a fallback.
+     *                         Note: originally this was used to type Select nodes in Java code,
+     *                         but that is no longer the case.
+     *                         It is preserved in case it is necessary for denotNamed, but this is unverified.
+     */
+    final def javaFindMember(name: Name, pre: Type, lookInCompanion: Boolean, required: FlagSet = EmptyFlags, excluded: FlagSet = EmptyFlags): Denotation =
       assert(ctx.isJava)
       inContext(ctx) {
 
@@ -53,7 +62,7 @@ object ContextOps:
         val directSearch = pre.findMember(name, pre, required, excluded)
 
         // 2. Try to search in companion class if current is an object.
-        def searchCompanionClass = if preSym.is(Flags.Module) then
+        def searchCompanionClass = if lookInCompanion && preSym.is(Flags.Module) then
           preSym.companionClass.thisType.findMember(name, pre, required, excluded)
           else NoDenotation
 

compiler/src/dotty/tools/dotc/typer/TypeAssigner.scala

@@ -156,7 +156,10 @@ trait TypeAssigner {
         val pre = maybeSkolemizePrefix(qualType, name)
         val mbr =
           if ctx.isJava then
-            ctx.javaFindMember(name, pre)
+            // don't look in the companion class here if qual is a module,
+            // we use backtracking to instead change the qual to the companion class
+            // if this fails.
+            ctx.javaFindMember(name, pre, lookInCompanion = false)
           else
             qualType.findMember(name, pre)