fix(printf): fix snprintf buffer termination

Fixes #7 (partly)

1 files changed, 13 insertions, 6 deletions

diff --git a/printf.c b/printf.c
index d9384f7..3cc7aa2 100644
--- a/printf.c
+++ b/printf.c
@@ -355,13 +355,13 @@ static size_t _vsnprintf(char* buffer, size_t buffer_len, const char* format, va
   unsigned int flags, width, precision, n;

   size_t idx = 0U;

 

-  while (idx < buffer_len) {

-    // end reached?

-    if (*format == (char)0) {

-      buffer[idx] = (char)0;

-      break;

-    }

+  // check if buffer is valid

+  if (!buffer) {

+    return 0U;

+  }

 

+  while ((idx < buffer_len) && *format)

+  {

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

     if (*format != '%') {

       // no

@@ -582,9 +582,16 @@ static size_t _vsnprintf(char* buffer, size_t buffer_len, const char* format, va
     }

   }

 

+  // termination

+  if (buffer_len > 0U) {

+    buffer[idx == buffer_len ? buffer_len - 1U : idx] = (char)0;

+  }

+

+  // return written chars without terminating \0

   return idx;

 }

 

+

 ///////////////////////////////////////////////////////////////////////////////

 

 int printf(const char* format, ...)