(nuttx) branch master updated: libc/wcsrtombs: Fix the wcsrtombs() according to the POSIX standard

[jerpelea]

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

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


The following commit(s) were added to refs/heads/master by this push:
     new fdc0b608b5 libc/wcsrtombs: Fix the wcsrtombs() according to the POSIX 
standard
fdc0b608b5 is described below

commit fdc0b608b5893a207ea37a276e0adade6ded3b62
Author: Tiago Medicci Serrano <tiago.medi...@espressif.com>
AuthorDate: Wed Feb 5 14:12:28 2025 -0300

    libc/wcsrtombs: Fix the wcsrtombs() according to the POSIX standard
    
    According to https://pubs.opengroup.org/onlinepubs/9799919799/, the
    expected behavior for the wcstombs() function is that it should
    convert the wide-character codes stoping conversion either when a
    character sequence exceeds the limit of n total bytes or if a null
    byte is stored. In the first case, the null-terminated value should
    not be appended to the dst buffer.
    
    Currently, no null-terminator is appended to the dst buffer, even
    when it's expected to be appended, generating erroneous output.
---
 libs/libc/wchar/lib_wcsrtombs.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/libs/libc/wchar/lib_wcsrtombs.c b/libs/libc/wchar/lib_wcsrtombs.c
index 70e6768a09..28c51ad6dc 100644
--- a/libs/libc/wchar/lib_wcsrtombs.c
+++ b/libs/libc/wchar/lib_wcsrtombs.c
@@ -40,5 +40,14 @@
 size_t wcsrtombs(FAR char *dst, FAR const wchar_t **src,
                  size_t len, FAR mbstate_t *ps)
 {
-  return wcsnrtombs(dst, src, SIZE_MAX, len, ps);
+  size_t ret;
+
+  ret = wcsnrtombs(dst, src, SIZE_MAX, len, ps);
+
+  if (dst != NULL && ret != (size_t)-1 && ret != len)
+    {
+      dst[ret] = '\0';
+    }
+
+  return ret;
 }