Preserve specialized generic static bindings

Author: Frotty

de.peeeq.wurstscript/src/main/java/de/peeeq/wurstscript/translation/imtranslation/EliminateGenerics.java

@@ -1443,6 +1443,15 @@ public void visit(ImVarArrayAccess access) {
             }
 
             private ImVar specializedGlobal(ImVar original) {
+                ImTranslator.Specialisation existing = translator.specialisationOf(original);
+                if (existing != null && translator.genericStaticOwnerOf(original) != null
+                    && !existing.typeArguments().isEmpty()) {
+                    // This access already names a concrete instantiation of the static field.
+                    // Its own binding wins over the type arguments of the function which happens
+                    // to contain it; in particular, specialising touch<pair> must not turn an
+                    // access produced by Box<int> into one for Box<pair>.
+                    return original;
+                }
                 ImClass owner = globalToClass.get(original);
                 if (owner == null) {
                     return original;

de.peeeq.wurstscript/src/test/java/tests/wurstscript/tests/LuaBackendAuditTests.java

@@ -446,6 +446,34 @@ public void tupleAssignmentCapturesLvalueBeforeRhs() throws IOException {
         assertFalse(compiled.contains("tupleCopy"));
     }
 
+    @Test
+    public void tupleSpecializationPreservesExplicitGenericStaticOwner() throws IOException {
+        test().testLua(true).executeProg().lines(
+            "package Test",
+            "native testSuccess()",
+            "tuple pair(int x, int y)",
+            "class Box<T:>",
+            "    static int counter",
+            "    static function setCounter(int value)",
+            "        counter = value",
+            "    static function incrementCounter()",
+            "        counter++",
+            "    static function getCounter() returns int",
+            "        return counter",
+            "function touch<T:>(T value)",
+            "    Box<int>.incrementCounter()",
+            "init",
+            "    Box<int>.setCounter(10)",
+            "    Box<pair>.setCounter(100)",
+            "    touch<pair>(pair(1, 2))",
+            "    if Box<int>.getCounter() == 11 and Box<pair>.getCounter() == 100",
+            "        testSuccess()"
+        );
+
+        String compiled = compiledLua("tupleSpecializationPreservesExplicitGenericStaticOwner");
+        assertFalse(compiled.contains("tupleCopy"));
+    }
+
     @Test
     public void compiletimeGenericArrayReplayLeavesAreSplit() {
         String compiled = compileLuaWithRunArgs(