* manual/stdio.texi (snprintf): Clarify handling of the trailing

       null byte in the output string.

1 files changed, 2 insertions, 0 deletions

diff --git a/manual/stdio.texi b/manual/stdio.texi
index c58ca22b2d..be769a538f 100644
--- a/manual/stdio.texi
+++ b/manual/stdio.texi
@@ -2341,6 +2341,8 @@ The @code{snprintf} function is similar to @code{sprintf}, except that
 the @var{size} argument specifies the maximum number of characters to
 produce.  The trailing null character is counted towards this limit, so
 you should allocate at least @var{size} characters for the string @var{s}.
+If @var{size} is zero, nothing, not even the null byte, shall be written and
+@var{s} may be a null pointer.
 
 The return value is the number of characters which would be generated
 for the given input, excluding the trailing null.  If this value is