From 46728e6cff04bcb9d6480166a980fdb48745b9b9 Mon Sep 17 00:00:00 2001
From: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Date: Sat, 11 Jul 2026 07:11:42 +0900
Subject: [PATCH] dln_find: Treat backslash as a separator when joining on
 DOSISH

When a search path component ends with a backslash, only '/' was
recognized as a trailing separator, so an extra '/' was inserted and
the resulting path contained a doubled separator.
---
 dln_find.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/dln_find.c b/dln_find.c
index 63e02f1f98a..2d2bd1bd296 100644
--- a/dln_find.c
+++ b/dln_find.c
@@ -234,7 +234,11 @@ dln_find_1(const char *fname, const char *path, char *fbuf, size_t size,
             }
 
             /* add a "/" between directory and filename */
+#if defined(DOSISH)
+            if (ep[-1] != '/' && ep[-1] != '\\')
+#else
             if (ep[-1] != '/')
+#endif
                 *bp++ = '/';
         }