- * This function reallocates successfully only if the previous allocation
- * to `stack' was `ptr'. If there was another memory allocation between
- * allocating `ptr' and this call, this routine will return NULL. The
- * NULL is also returned if the `size' does not fit to current stack
- * and allocating new block would require slow copying of the data. It
- * is left to the caller to decide whether to allocate new pointer and
- * copy the old data in case this function returns NULL.
+ * If the reallocation from `stack' fails, this function will allocate
+ * new block of size of `size' bytes from `stack' and copy the data from
+ * `ptr' to the new memory block.