Fix symbol table entry for friend operators

Now unqualified friend declarations/definitions can be ignored or
renamed as expected.

Note: previous commit regressed this for friends that were not operators
but now the symbol tables are correct for operators and non-operators
alike.

CHANGES.current

@@ -7,6 +7,11 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.2.1 (in progress)
 ===========================
 
+2024-01-15: wsfulton
+            https://sourceforge.net/p/swig/bugs/960/
+            Fix so that friend operators within a namespace can be correctly ignored
+            or renamed.
+
 2024-01-15: wsfulton
             https://sourceforge.net/p/swig/bugs/807/
             Wrap friend functions that are defined or declared within a namespace.

Examples/test-suite/rename_scope.i

@@ -48,9 +48,16 @@ namespace oss
   } 
 } 
 
-%rename("equals") operator==;
+// Note not: Utilities::Bucket::operator==
+%rename("equals") Utilities::operator==;
+
+%ignore Utilities::operator<<;
+namespace Utilities {
+  %ignore operator>>;
+}
 
 %inline %{
+#include <iostream>
 
   namespace Utilities {
     class Bucket
@@ -60,6 +67,8 @@ namespace oss
       friend bool operator==(const Bucket& lhs, const Bucket& rhs){
 	return ( rhs.m_left == lhs.m_left );
       }
+      friend std::ostream& operator<<(std::ostream&, const Bucket &);
+      friend std::ostream& operator>>(std::ostream&, const Bucket &);
     private:
       int m_left;
     };

Source/CParse/parser.y

@@ -426,13 +426,18 @@ static void add_symbols(Node *n) {
 	old_scope = Swig_symbol_popscope();
 	Namespaceprefix = Swig_symbol_qualifiedscopename(0);
 	if (!prefix) {
+	  /* To check - this should probably apply to operators too */
 	  if (name && !is_operator(name) && Namespaceprefix) {
 	    String *friendusing = NewStringf("using namespace %s;", Namespaceprefix);
 	    Setattr(n, "friendusing", friendusing);
 	    Delete(friendusing);
 	  }
+	} else {
+	  /* Qualified friend declarations should not be possible as they are ignored in the parse tree */
+	  /* TODO: uncomment out for swig-4.3.0
+	  assert(0);
+	  */
 	}
-	Namespaceprefix = 0;
       } else if (Equal(nodeType(n), "using")) {
 	String *uname = Getattr(n, "uname");
 	Node *cls = current_class ? current_class : currentOuterClass; /* Current class seems to vary depending on whether it is a template class or a plain class */