Function ch_enlargebufs

extern/editline/src/chared.c:499–583

ch_enlargebufs(): * Enlarge line buffer to be able to hold twice as much characters. * Returns 1 if successful, 0 if not. */

 *	Returns 1 if successful, 0 if not.
 */
protected int
ch_enlargebufs(EditLine *el, size_t addlen)
{
	size_t sz, newsz;
	Char *newbuffer, *oldbuf, *oldkbuf;

	sz = (size_t)(el->el_line.limit - el->el_line.buffer + EL_LEAVE);
	newsz = sz * 2;
	/*
	 * If newly required length is longer than current buffer, we need
	 * to make the buffer big enough to hold both old and new stuff.
	 */
	if (addlen > sz) {
		while(newsz - sz < addlen)
			newsz *= 2;
	}

	/*
	 * Reallocate line buffer.
	 */
	newbuffer = el_realloc(el->el_line.buffer, newsz * sizeof(*newbuffer));
	if (!newbuffer)
		return 0;

	/* zero the newly added memory, leave old data in */
	(void) memset(&newbuffer[sz], 0, (newsz - sz) * sizeof(*newbuffer));
	    
	oldbuf = el->el_line.buffer;

	el->el_line.buffer = newbuffer;
	el->el_line.cursor = newbuffer + (el->el_line.cursor - oldbuf);
	el->el_line.lastchar = newbuffer + (el->el_line.lastchar - oldbuf);
	/* don't set new size until all buffers are enlarged */
	el->el_line.limit  = &newbuffer[sz - EL_LEAVE];

	/*
	 * Reallocate kill buffer.
	 */
	newbuffer = el_realloc(el->el_chared.c_kill.buf, newsz *
	    sizeof(*newbuffer));
	if (!newbuffer)
		return 0;

	/* zero the newly added memory, leave old data in */
	(void) memset(&newbuffer[sz], 0, (newsz - sz) * sizeof(*newbuffer));

	oldkbuf = el->el_chared.c_kill.buf;

	el->el_chared.c_kill.buf = newbuffer;
	el->el_chared.c_kill.last = newbuffer +
					(el->el_chared.c_kill.last - oldkbuf);
	el->el_chared.c_kill.mark = el->el_line.buffer +
					(el->el_chared.c_kill.mark - oldbuf);

	/*
	 * Reallocate undo buffer.
	 */
	newbuffer = el_realloc(el->el_chared.c_undo.buf,