From ca9aeeec1ffdb09aa938edf507bfddfa0a8fdcbb Mon Sep 17 00:00:00 2001
From: Fotis Panagiotopoulos <f.panag@amco.gr>
Date: Tue, 18 Oct 2022 13:19:10 +0300
Subject: [PATCH] freopen: Added flush of the read buffers.

---
 libs/libc/stdio/lib_freopen.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/libs/libc/stdio/lib_freopen.c b/libs/libc/stdio/lib_freopen.c
index ca4d42bc78b..2958dfdaace 100644
--- a/libs/libc/stdio/lib_freopen.c
+++ b/libs/libc/stdio/lib_freopen.c
@@ -100,9 +100,16 @@ FAR FILE *freopen(FAR const char *path, FAR const char *mode,
           return NULL;
         }
 
-      /* Flush the stream and duplicate the new fd to it */
+      /* Flush the stream and invalidate the read buffer. */
 
       fflush(stream);
+
+#ifndef CONFIG_STDIO_DISABLE_BUFFERING
+      lib_rdflush(stream);
+#endif
+
+      /* Duplicate the new fd to the stream. */
+
       ret = dup2(fd, fileno(stream));
       close(fd);
       if (ret < 0)