From 0c2797f9cf14d3657fb04972b940db9048ebb090 Mon Sep 17 00:00:00 2001
From: Devrim Gunduz <devrim@gunduz.org>
Date: Thu, 9 Jul 2026 13:38:12 +0300
Subject: [PATCH] PostgreSQL 19 fixes

  replace `bits8 *pa, *pb` with `uint8 *pa, *pb` in hamming().
  PG19 dropped the `bits8` typedef (previously `typedef uint8 bits8;` in
  c.h) in favor of using `uint8` directly; VARBITS() now returns
  `uint8 *` instead of `bits8 *`. Under PG18 and earlier this compiled
  fine because `bits8` was a valid alias, but on PG19 the identifier is
  gone entirely, so the compiler treats `bits8 *pa, *pb;` as an
  expression rather than a declaration, producing "use of undeclared
  identifier 'bits8'" (clang) / "unknown type name 'bits8'" (gcc), plus
  the cascading "undeclared identifier pa/pb" and
  "assignment ... from incompatible pointer type 'uint8 *'" errors

Hacked by Claude, tested by me.
---
 hamming.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hamming.c b/hamming.c
index 862ed7f..a1c62b0 100644
--- a/hamming.c
+++ b/hamming.c
@@ -44,7 +44,7 @@ hamming(PG_FUNCTION_ARGS)
 {
 	VarBit		*a, *b;
 	int		alen, blen;
-	bits8		*pa, *pb;
+	uint8		*pa, *pb;
 	int		maxlen;
 	float8		res = 0.0;
 	int		i;