air: fix field falsly detected to be redefined

fixes #3369

src/dev/flang/air/Clazz.java

@@ -1009,6 +1009,12 @@ private AbstractFeature findRedefinition(AbstractFeature f)
     // first look in the feature itself
     AbstractFeature result = _flu.lookupFeature(feature(), fn, f);
 
+    if (!result.redefinesFull().contains(f) && result != f)
+      {
+        // feature with same name, but not a redefinition
+        result = null;
+      }
+
     // the inherited feature might not be
     // visible to the inheriting feature
     var chain = tf.findInheritanceChain(f.outer());
@@ -1017,6 +1023,11 @@ private AbstractFeature findRedefinition(AbstractFeature f)
         for (var p: chain)
           {
             result = _flu.lookupFeature(p.calledFeature(), fn, f);
+            if (!result.redefinesFull().contains(f) && result != f)
+              {
+                // feature with same name, but not a redefinition
+                result = null;
+              }
             if (result != null)
               {
                 break;

src/dev/flang/ast/AbstractFeature.java

@@ -28,6 +28,8 @@
 
 import java.util.Arrays;
 import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import dev.flang.util.Errors;
 import dev.flang.util.FuzionConstants;
@@ -1881,6 +1883,19 @@ public boolean isNonArgumentField()
   }
 
 
+  /**
+   * In constrast to redefines() this does not just contain direct redefines()
+   * but also redefinitions of redefinitions of arbitrary depth.
+   */
+  public Set<AbstractFeature> redefinesFull()
+  {
+    return redefines()
+      .stream()
+      .flatMap(x -> Stream.concat(Stream.of(x), x.redefinesFull().stream()))
+      .collect(Collectors.toSet());
+  }
+
+
   /**
    * this feature as a human readable string
    */

tests/reg_issue3369/Makefile

@@ -0,0 +1,26 @@
+# This file is part of the Fuzion language implementation.
+#
+# The Fuzion language implementation is free software: you can redistribute it
+# and/or modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation, version 3 of the License.
+#
+# The Fuzion language implementation is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License along with The
+# Fuzion language implementation.  If not, see <https://www.gnu.org/licenses/>.
+
+
+# -----------------------------------------------------------------------
+#
+#  Tokiwa Software GmbH, Germany
+#
+#  Source code of Fuzion test Makefile
+#
+# -----------------------------------------------------------------------
+
+override NAME = reg_issue3369
+export FUZION_OPTIONS=-sourceDirs=.
+include ../simple.mk

tests/reg_issue3369/child.fz

@@ -0,0 +1,6 @@
+public child : parent is
+
+  redef get_name => "CHILD"
+
+  # NYI: This caused a java exception
+  name := get_name

tests/reg_issue3369/parent.fz

@@ -0,0 +1,7 @@
+public parent is
+
+  module get_name => "PARENT"
+
+  name := get_name
+
+  public introduce => "I'm $name"

tests/reg_issue3369/reg_issue3369.fz

@@ -0,0 +1,26 @@
+# This file is part of the Fuzion language implementation.
+#
+# The Fuzion language implementation is free software: you can redistribute it
+# and/or modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation, version 3 of the License.
+#
+# The Fuzion language implementation is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License along with The
+# Fuzion language implementation.  If not, see <https://www.gnu.org/licenses/>.
+
+
+# -----------------------------------------------------------------------
+#
+#  Tokiwa Software GmbH, Germany
+#
+#  Source code of Fuzion test reg_issue3369
+#
+# -----------------------------------------------------------------------
+
+reg_issue3369 =>
+
+  say child.introduce

tests/reg_issue3369/reg_issue3369.fz.expected_out

@@ -0,0 +1 @@
+I'm CHILD

tests/visibility_modules/main.fz

@@ -39,5 +39,4 @@ m =>
 
   say b.get_any.as_string // indirectly calling private feature
 
-  # NYI this does not work yet
-  # say b.get_field
+  say b.get_field

tests/visibility_modules/main.fz.expected_out

@@ -9,3 +9,4 @@ hello_a from b
 calling b.get_aa.aaa
 aaa
 priv
+0