From 56c715af40ed1cad1a3b2a29de50e7ceaa9911e4 Mon Sep 17 00:00:00 2001
From: bbbradsmith <bbbradsmith@users.noreply.github.com>
Date: Wed, 3 May 2023 01:14:27 -0400
Subject: [PATCH 1/2] Error for struct/union with a duplicate member #2015

---
 src/cc65/symtab.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/cc65/symtab.c b/src/cc65/symtab.c
index 72a2ac007..d9270f604 100644
--- a/src/cc65/symtab.c
+++ b/src/cc65/symtab.c
@@ -793,6 +793,8 @@ static int HandleSymRedefinition (SymEntry* Sym, const Type* T, unsigned Flags)
                 */
                 Error ("Redeclaration of enumerator constant '%s'", Sym->Name);
                 Sym = 0;
+            } else if (Flags & SC_STRUCTFIELD) {
+                Error ("Duplicate member '%s'", Sym->Name);
             }
         }
     }

From 84eafb7f9c255d6a82a8062a6d8a8f3c0eb60a72 Mon Sep 17 00:00:00 2001
From: bbbradsmith <bbbradsmith@users.noreply.github.com>
Date: Wed, 3 May 2023 21:09:03 -0400
Subject: [PATCH 2/2] err test for struct with duplicate member

---
 test/err/struct-duplicate-member.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 test/err/struct-duplicate-member.c

diff --git a/test/err/struct-duplicate-member.c b/test/err/struct-duplicate-member.c
new file mode 100644
index 000000000..30cd06207
--- /dev/null
+++ b/test/err/struct-duplicate-member.c
@@ -0,0 +1,17 @@
+/* Ensure that a duplicate member in a struct produces an error.
+** https://github.com/cc65/cc65/issues/2015
+*/
+
+struct bads {
+    int a;
+    int a; /* this is an error */
+};
+
+union badu {
+    int a, a; /* also an error */
+};
+
+int main(void)
+{
+    return 0;
+}