buffer: add buffer_put0 to store a NUL terminated string

buffer.c

@@ -39,11 +39,15 @@ void buffer_release(Buffer *buf) {
 bool buffer_put(Buffer *buf, const void *data, size_t len) {
 	if (!buffer_grow(buf, len))
 		return false;
-	memcpy(buf->data, data, len);
+	memmove(buf->data, data, len);
 	buf->len = len;
 	return true;
 }
 
+bool buffer_put0(Buffer *buf, const char *data) {
+	return buffer_put(buf, data, strlen(data)+1);
+}
+
 bool buffer_append(Buffer *buf, const void *data, size_t len) {
 	size_t rem = buf->size - buf->len;
 	if (len > rem && !buffer_grow(buf, buf->size + len - rem))

buffer.h

@@ -21,6 +21,8 @@ bool buffer_grow(Buffer*, size_t size);
 void buffer_truncate(Buffer*);
 /* replace buffer content with given data, growing the buffer if needed */
 bool buffer_put(Buffer*, const void *data, size_t len);
+/* same but with NUL-terminated data */
+bool buffer_put0(Buffer*, const char *data);
 /* append futher content to the end of the buffer data */
 bool buffer_append(Buffer*, const void *data, size_t len);
 /* append NUl-terminated data */