Fix a bug in wcsnrtombs

__d is a char * destination buffer, so __b is already the byte capacity.
Dividing by sizeof(wchar_t) makes no sense here, it was likely copy-pasted
from mbsnrtowcs (where the destination is wchar_t *). The first branch also
fails to limit __n (the byte write cap) to __b, so overflows are possible when
a wide character produces multi-byte output. The second branch (else) correctly
limits __n to __b.

This commit replaces the broken two-branch logic with the simple correct
pattern matching wcsrtombs, and adds two tests two prove that nothing broke.

1 files changed, 2 insertions, 0 deletions

diff --git a/tests/Makefile b/tests/Makefile
index 71fb930..adea381 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -94,6 +94,8 @@ RUNTIME_TARGETS= \
         test_vsnprintf_static         \
         test_vsprintf                 \
         test_wcrtomb                  \
+        test_wcsnrtombs_dynamic       \
+        test_wcsnrtombs_static        \
         test_wcscat_static_write      \
         test_wcscpy_static_write      \
         test_wcsncat_static_write     \