From d5f66e5583bf8f29acc31c545d84325baf20bdf9 Mon Sep 17 00:00:00 2001
From: SPRESENSE <41312067+SPRESENSE@users.noreply.github.com>
Date: Fri, 27 Nov 2020 19:46:07 +0900
Subject: [PATCH] stdio/lib_clearerr: Did not clear stream buffer flags in
 clearerr

Stream buffer flags has a dependency with allocated buffer,
and it cannot clear without buffer operation.

Change clearerr to keep buffer flags to prevent unexpected
buffer operation.
---
 libs/libc/stdio/lib_clearerr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libs/libc/stdio/lib_clearerr.c b/libs/libc/stdio/lib_clearerr.c
index 20a69c8996..39e6b74da9 100644
--- a/libs/libc/stdio/lib_clearerr.c
+++ b/libs/libc/stdio/lib_clearerr.c
@@ -48,6 +48,6 @@
 
 void clearerr(FAR FILE *stream)
 {
-  stream->fs_flags = 0;
+  stream->fs_flags &= (__FS_FLAG_LBF | __FS_FLAG_UBF);
 }
 #endif /* CONFIG_FILE_STREAM */