From 096c6ef84ff367ccee30eb44d9833fe3f61c45cc Mon Sep 17 00:00:00 2001
From: "jan.nijtmans" <nijtmans@users.sourceforge.net>
Date: Tue, 4 Apr 2023 22:47:27 +0000
Subject: Fix [6390566ecd]: Testcase cmdAH-4.3.13.00DC0000.tail.utf-32.tcl8.a
 fails sometimes

---
 generic/tclEncoding.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/generic/tclEncoding.c b/generic/tclEncoding.c
index 689fa50..e9b0cce 100644
--- a/generic/tclEncoding.c
+++ b/generic/tclEncoding.c
@@ -2821,6 +2821,11 @@ Utf32ToUtfProc(
 	if ((unsigned)ch - 1 < 0x7F) {
 	    *dst++ = (ch & 0xFF);
 	} else {
+#if TCL_UTF_MAX < 4
+	    if (!HIGH_SURROGATE(prev) && LOW_SURROGATE(ch)) {
+		*dst = 0; /* In case of lower surrogate, don't try to combine */
+	    }
+#endif
 	    dst += Tcl_UniCharToUtf(ch, dst);
 	}
 	src += 4;
-- 
cgit v0.12