Don't compactify Java inner class names

Author: griggt

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

@@ -481,7 +481,7 @@ object SymDenotations {
           prefix = prefix.exclude(ModuleClassName)
         def qualify(n: SimpleName) =
           val qn = kind(prefix.toTermName, if (filler.isEmpty) n else termName(filler + n))
-          if kind == FlatName then qn.compactified else qn
+          if kind == FlatName && !encl.is(JavaDefined) then qn.compactified else qn
         val fn = name replace {
           case name: SimpleName => qualify(name)
           case name @ AnyQualifiedName(_, _) => qualify(name.mangled.toSimpleName)

tests/run/java-longnames/Long_1.java

@@ -0,0 +1,6 @@
+package p;
+
+public class Long_1 {
+    public static class ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ_1 {
+    }
+}

tests/run/java-longnames/Test_2.scala

@@ -0,0 +1,9 @@
+import p._
+
+object Test extends App {
+  println(
+    new Long_1.ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ_1()
+      .getClass
+      .getName
+  )
+}