smart_append working!

#include <string.h>
#include "exercise.h"

int smart_append(TextBuffer* dest, const char* src) {
  /* REMEMBER: Length != Size */
  int src_len, remaining_space;
  int current_buf_len;
  int const MAX_BUF_SIZE = 64;
  if (dest == NULL || src == NULL)
    return 1;
  src_len = strlen(src);
  current_buf_len = strlen(dest->buffer);
  /* Sub buffer len from max_size, acct'ing for '\0' */
  remaining_space = MAX_BUF_SIZE - (current_buf_len + 1);
  if (src_len > remaining_space) {
    /* Cp as much as possible, update & return 1 */
    strncat(dest->buffer, src, remaining_space);
    dest->length = MAX_BUF_SIZE - 1;
    return 1;
  } else {
    strncat(dest->buffer, src, src_len);
    dest->length += src_len;
    return 0;
  }
}