[newlib-cygwin/main] __sfvwrite_r: call __sputc_r rather than putc in __SCLE case

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=6ccbfe6a3d8a2aedb2c6f80bcc03bf946acc1b6c

commit 6ccbfe6a3d8a2aedb2c6f80bcc03bf946acc1b6c
Author:     Corinna Vinschen <corinna@vinschen.de>
AuthorDate: Fri Nov 17 17:00:54 2023 +0100
Commit:     Corinna Vinschen <corinna@vinschen.de>
CommitDate: Fri Nov 17 17:09:42 2023 +0100

    __sfvwrite_r: call __sputc_r rather than putc in __SCLE case
    
    __sfvwrite_r is called under lock.  There's no reason to call
    putc, locking the file recursively.  Add a comment that locking
    is required when calling __sfvwrite_r.
    
    Fixes: 49d64538cd20 ("* libc/include/stdio.h (FILE): define __SCLE for "convert line endings" for Cygwin.")
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 newlib/libc/stdio/fvwrite.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/newlib/libc/stdio/fvwrite.c b/newlib/libc/stdio/fvwrite.c
index 34361cb8d135..fc79951032ad 100644
--- a/newlib/libc/stdio/fvwrite.c
+++ b/newlib/libc/stdio/fvwrite.c
@@ -40,6 +40,9 @@
 /*
  * Write some memory regions.  Return zero on success, EOF on error.
  *
+ * On systems supporting threads, this function *must* be called under
+ * _newlib_flockfile_start locking.
+ *
  * This routine is large and unsightly, but most of the ugliness due
  * to the three different kinds of output buffering is handled here.
  */
@@ -74,7 +77,7 @@ __sfvwrite_r (struct _reent *ptr,
           GETIOV (;);
           while (len > 0)
             {
-              if (putc (*p, fp) == EOF)
+              if (__sputc_r (ptr, *p, fp) == EOF)
                 return EOF;
               p++;
               len--;