[incubator-nuttx] branch master updated: libs/libc/stdio: fix ungetc operation

[xi...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new ec4a615f6c libs/libc/stdio: fix ungetc operation
ec4a615f6c is described below

commit ec4a615f6cfaed50d20fc4176dc18254533f9f52
Author: Petro Karashchenko <pe...@gmail.com>
AuthorDate: Fri Oct 14 11:54:56 2022 +0200

    libs/libc/stdio: fix ungetc operation
    
    Do not modify errno in case of failure
    Return EOF if the value of c equals to EOF
    
    Signed-off-by: Petro Karashchenko <pe...@gmail.com>
---
 libs/libc/stdio/lib_ungetc.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/libs/libc/stdio/lib_ungetc.c b/libs/libc/stdio/lib_ungetc.c
index bf4a5833cd..f5ebea1e39 100644
--- a/libs/libc/stdio/lib_ungetc.c
+++ b/libs/libc/stdio/lib_ungetc.c
@@ -43,11 +43,10 @@ int ungetc(int c, FAR FILE *stream)
   int nungotten;
 #endif
 
-  /* Verify that a non-NULL stream was provided */
+  /* Verify that a non-NULL stream was provided and c is not EOF */
 
-  if (!stream)
+  if (!stream || c == EOF)
     {
-      set_errno(EBADF);
       return EOF;
     }
 
@@ -55,7 +54,6 @@ int ungetc(int c, FAR FILE *stream)
 
   if ((stream->fs_fd < 0) || ((stream->fs_oflags & O_RDOK) == 0))
     {
-      set_errno(EBADF);
       return EOF;
     }
 
@@ -70,7 +68,6 @@ int ungetc(int c, FAR FILE *stream)
   else
 #endif
     {
-      set_errno(ENOMEM);
       return EOF;
     }
 }