fix(printf): use null output function for nullptr buffer

Improving #11

1 files changed, 13 insertions, 1 deletions

diff --git a/printf.c b/printf.c
index d373781..edc0a4e 100644
--- a/printf.c
+++ b/printf.c
@@ -70,12 +70,19 @@ typedef void (*out_fct_type)(char character, char* buffer, size_t idx, size_t ma
 // internal buffer output

 static inline void _out_buffer(char character, char* buffer, size_t idx, size_t maxlen)

 {

-  if (!!buffer && (idx < maxlen)) {

+  if (idx < maxlen) {

     buffer[idx] = character;

   }

 }

 

 

+// internal null output

+static inline void _out_null(char character, char* buffer, size_t idx, size_t maxlen)

+{

+  (void)character; (void)buffer; (void)idx; (void)maxlen;

+}

+

+

 // internal _putchar wrapper

 static inline void _out_char(char character, char* buffer, size_t idx, size_t maxlen)

 {

@@ -363,6 +370,11 @@ static int _vsnprintf(out_fct_type out, char* buffer, const size_t maxlen, const
   unsigned int flags, width, precision, n;

   size_t idx = 0U;

 

+  if (!buffer) {

+    // use null output function

+    out = _out_null;

+  }

+

   while (*format)

   {

     // format specifier?  %[flags][width][.precision][length]