Fix an integer overflow issue (#809)

Prevent an integer overflow issue in function opj_pi_create_decode of
pi.c.
static void opj_get_all_encoding_parameters(   const opj_image_t *p_image,
                                        const opj_cp_t *p_cp,
                                        OPJ_UINT32 tileno,
                                        OPJ_INT32 * p_tx0,
                                        OPJ_INT32 * p_tx1,
                                        OPJ_INT32 * p_ty0,
                                        OPJ_INT32 * p_ty1,
                                        OPJ_UINT32 * p_dx_min,
                                        OPJ_UINT32 * p_dy_min,
                                        OPJ_UINT32 * p_max_prec,
                                        OPJ_UINT32 * p_max_res,
                                        OPJ_UINT32 ** p_resolutions )
{
	/* loop*/
	OPJ_UINT32 compno, resno;

	/* pointers*/
	const opj_tcp_t *tcp = 00;
	const opj_tccp_t * l_tccp = 00;
	const opj_image_comp_t * l_img_comp = 00;

	/* to store l_dx, l_dy, w and h for each resolution and component.*/
	OPJ_UINT32 * lResolutionPtr;

	/* position in x and y of tile*/
	OPJ_UINT32 p, q;

	/* non-corrected (in regard to image offset) tile offset */
	OPJ_UINT32 l_tx0, l_ty0;

	/* preconditions in debug*/
	assert(p_cp != 00);
	assert(p_image != 00);
	assert(tileno < p_cp->tw * p_cp->th);

	/* initializations*/
	tcp = &p_cp->tcps [tileno];
	l_tccp = tcp->tccps;
	l_img_comp = p_image->comps;

	/* position in x and y of tile*/
	p = tileno % p_cp->tw;
	q = tileno / p_cp->tw;

	/* here calculation of tx0, tx1, ty0, ty1, maxprec, l_dx and l_dy */
	l_tx0 = p_cp->tx0 + p * p_cp->tdx; /* can't be greater than p_image->x1 so won't overflow */
	*p_tx0 = (OPJ_INT32)opj_uint_max(l_tx0, p_image->x0);
	*p_tx1 = (OPJ_INT32)opj_uint_min(opj_uint_adds(l_tx0, p_cp->tdx), p_image->x1);
	l_ty0 = p_cp->ty0 + q * p_cp->tdy; /* can't be greater than p_image->y1 so won't overflow */
	*p_ty0 = (OPJ_INT32)opj_uint_max(l_ty0, p_image->y0);
	*p_ty1 = (OPJ_INT32)opj_uint_min(opj_uint_adds(l_ty0, p_cp->tdy), p_image->y1);

	/* max precision and resolution is 0 (can only grow)*/
	*p_max_prec = 0;
	*p_max_res = 0;

	/* take the largest value for dx_min and dy_min*/
	*p_dx_min = 0x7fffffff;
	*p_dy_min = 0x7fffffff;

	for (compno = 0; compno < p_image->numcomps; ++compno) {
		/* aritmetic variables to calculate*/
		OPJ_UINT32 l_level_no;
		OPJ_INT32 l_rx0, l_ry0, l_rx1, l_ry1;
		OPJ_INT32 l_px0, l_py0, l_px1, py1;
		OPJ_UINT32 l_product;
		OPJ_INT32 l_tcx0, l_tcy0, l_tcx1, l_tcy1;
		OPJ_UINT32 l_pdx, l_pdy , l_pw , l_ph;

		lResolutionPtr = p_resolutions[compno];

		l_tcx0 = opj_int_ceildiv(*p_tx0, (OPJ_INT32)l_img_comp->dx);
		l_tcy0 = opj_int_ceildiv(*p_ty0, (OPJ_INT32)l_img_comp->dy);
		l_tcx1 = opj_int_ceildiv(*p_tx1, (OPJ_INT32)l_img_comp->dx);
		l_tcy1 = opj_int_ceildiv(*p_ty1, (OPJ_INT32)l_img_comp->dy);

		if (l_tccp->numresolutions > *p_max_res) {
			*p_max_res = l_tccp->numresolutions;
		}

		/* use custom size for precincts*/
		l_level_no = l_tccp->numresolutions;
		for (resno = 0; resno < l_tccp->numresolutions; ++resno) {
			OPJ_UINT32 l_dx, l_dy;

			--l_level_no;
			
			/* precinct width and height*/
			l_pdx = l_tccp->prcw[resno];
			l_pdy = l_tccp->prch[resno];
			*lResolutionPtr++ = l_pdx;
			*lResolutionPtr++ = l_pdy;
			l_dx = l_img_comp->dx * (1u << (l_pdx + l_level_no));
			l_dy = l_img_comp->dy * (1u << (l_pdy + l_level_no));
			/* take the minimum size for l_dx for each comp and resolution*/
			*p_dx_min = (OPJ_UINT32)opj_int_min((OPJ_INT32)*p_dx_min, (OPJ_INT32)l_dx);
			*p_dy_min = (OPJ_UINT32)opj_int_min((OPJ_INT32)*p_dy_min, (OPJ_INT32)l_dy);

			/* various calculations of extents*/
			l_rx0 = opj_int_ceildivpow2(l_tcx0, (OPJ_INT32)l_level_no);
			l_ry0 = opj_int_ceildivpow2(l_tcy0, (OPJ_INT32)l_level_no);
			l_rx1 = opj_int_ceildivpow2(l_tcx1, (OPJ_INT32)l_level_no);
			l_ry1 = opj_int_ceildivpow2(l_tcy1, (OPJ_INT32)l_level_no);
			l_px0 = opj_int_floordivpow2(l_rx0, (OPJ_INT32)l_pdx) << l_pdx;
			l_py0 = opj_int_floordivpow2(l_ry0, (OPJ_INT32)l_pdy) << l_pdy;
			l_px1 = opj_int_ceildivpow2(l_rx1, (OPJ_INT32)l_pdx) << l_pdx;
			py1 = opj_int_ceildivpow2(l_ry1, (OPJ_INT32)l_pdy) << l_pdy;
			l_pw = (l_rx0==l_rx1)?0:(OPJ_UINT32)((l_px1 - l_px0) >> l_pdx);
			l_ph = (l_ry0==l_ry1)?0:(OPJ_UINT32)((py1 - l_py0) >> l_pdy);
			*lResolutionPtr++ = l_pw;
			*lResolutionPtr++ = l_ph;
			l_product = l_pw * l_ph;
			
            /* update precision*/
			if (l_product > *p_max_prec) {
				*p_max_prec = l_product;
			}

		}
		++l_tccp;
		++l_img_comp;
	}
}

static void opj_get_all_encoding_parameters(   const opj_image_t *p_image,
                                        const opj_cp_t *p_cp,
                                        OPJ_UINT32 tileno,
                                        OPJ_INT32 * p_tx0,
                                        OPJ_INT32 * p_tx1,
                                        OPJ_INT32 * p_ty0,
                                        OPJ_INT32 * p_ty1,
                                        OPJ_UINT32 * p_dx_min,
                                        OPJ_UINT32 * p_dy_min,
                                        OPJ_UINT32 * p_max_prec,
                                        OPJ_UINT32 * p_max_res,
                                        OPJ_UINT32 ** p_resolutions )
{
	/* loop*/
	OPJ_UINT32 compno, resno;

	/* pointers*/
	const opj_tcp_t *tcp = 00;
	const opj_tccp_t * l_tccp = 00;
	const opj_image_comp_t * l_img_comp = 00;

	/* to store l_dx, l_dy, w and h for each resolution and component.*/
	OPJ_UINT32 * lResolutionPtr;

	/* position in x and y of tile*/
	OPJ_UINT32 p, q;

	/* non-corrected (in regard to image offset) tile offset */
	OPJ_UINT32 l_tx0, l_ty0;

	/* preconditions in debug*/
	assert(p_cp != 00);
	assert(p_image != 00);
	assert(tileno < p_cp->tw * p_cp->th);

	/* initializations*/
	tcp = &p_cp->tcps [tileno];
	l_tccp = tcp->tccps;
	l_img_comp = p_image->comps;

	/* position in x and y of tile*/
	p = tileno % p_cp->tw;
	q = tileno / p_cp->tw;

	/* here calculation of tx0, tx1, ty0, ty1, maxprec, l_dx and l_dy */
	l_tx0 = p_cp->tx0 + p * p_cp->tdx; /* can't be greater than p_image->x1 so won't overflow */
	*p_tx0 = (OPJ_INT32)opj_uint_max(l_tx0, p_image->x0);
	*p_tx1 = (OPJ_INT32)opj_uint_min(opj_uint_adds(l_tx0, p_cp->tdx), p_image->x1);
	l_ty0 = p_cp->ty0 + q * p_cp->tdy; /* can't be greater than p_image->y1 so won't overflow */
	*p_ty0 = (OPJ_INT32)opj_uint_max(l_ty0, p_image->y0);
	*p_ty1 = (OPJ_INT32)opj_uint_min(opj_uint_adds(l_ty0, p_cp->tdy), p_image->y1);

	/* max precision and resolution is 0 (can only grow)*/
	*p_max_prec = 0;
	*p_max_res = 0;

	/* take the largest value for dx_min and dy_min*/
	*p_dx_min = 0x7fffffff;
	*p_dy_min = 0x7fffffff;

	for (compno = 0; compno < p_image->numcomps; ++compno) {
		/* aritmetic variables to calculate*/
		OPJ_UINT32 l_level_no;
		OPJ_INT32 l_rx0, l_ry0, l_rx1, l_ry1;
		OPJ_INT32 l_px0, l_py0, l_px1, py1;
		OPJ_UINT32 l_product;
		OPJ_INT32 l_tcx0, l_tcy0, l_tcx1, l_tcy1;
		OPJ_UINT32 l_pdx, l_pdy , l_pw , l_ph;

		lResolutionPtr = p_resolutions[compno];

		l_tcx0 = opj_int_ceildiv(*p_tx0, (OPJ_INT32)l_img_comp->dx);
		l_tcy0 = opj_int_ceildiv(*p_ty0, (OPJ_INT32)l_img_comp->dy);
		l_tcx1 = opj_int_ceildiv(*p_tx1, (OPJ_INT32)l_img_comp->dx);
		l_tcy1 = opj_int_ceildiv(*p_ty1, (OPJ_INT32)l_img_comp->dy);

		if (l_tccp->numresolutions > *p_max_res) {
			*p_max_res = l_tccp->numresolutions;
		}

		/* use custom size for precincts*/
		l_level_no = l_tccp->numresolutions;
		for (resno = 0; resno < l_tccp->numresolutions; ++resno) {
			OPJ_UINT32 l_dx, l_dy;

			--l_level_no;
			
			/* precinct width and height*/
			l_pdx = l_tccp->prcw[resno];
			l_pdy = l_tccp->prch[resno];
			*lResolutionPtr++ = l_pdx;
			*lResolutionPtr++ = l_pdy;
			l_dx = l_img_comp->dx * (1u << (l_pdx + l_level_no));
			l_dy = l_img_comp->dy * (1u << (l_pdy + l_level_no));
			/* take the minimum size for l_dx for each comp and resolution*/
			*p_dx_min = (OPJ_UINT32)opj_int_min((OPJ_INT32)*p_dx_min, (OPJ_INT32)l_dx);
			*p_dy_min = (OPJ_UINT32)opj_int_min((OPJ_INT32)*p_dy_min, (OPJ_INT32)l_dy);

			/* various calculations of extents*/
			l_rx0 = opj_int_ceildivpow2(l_tcx0, (OPJ_INT32)l_level_no);
			l_ry0 = opj_int_ceildivpow2(l_tcy0, (OPJ_INT32)l_level_no);
			l_rx1 = opj_int_ceildivpow2(l_tcx1, (OPJ_INT32)l_level_no);
			l_ry1 = opj_int_ceildivpow2(l_tcy1, (OPJ_INT32)l_level_no);
			l_px0 = opj_int_floordivpow2(l_rx0, (OPJ_INT32)l_pdx) << l_pdx;
			l_py0 = opj_int_floordivpow2(l_ry0, (OPJ_INT32)l_pdy) << l_pdy;
			l_px1 = opj_int_ceildivpow2(l_rx1, (OPJ_INT32)l_pdx) << l_pdx;
			py1 = opj_int_ceildivpow2(l_ry1, (OPJ_INT32)l_pdy) << l_pdy;
			l_pw = (l_rx0==l_rx1)?0:(OPJ_UINT32)((l_px1 - l_px0) >> l_pdx);
			l_ph = (l_ry0==l_ry1)?0:(OPJ_UINT32)((py1 - l_py0) >> l_pdy);
			*lResolutionPtr++ = l_pw;
			*lResolutionPtr++ = l_ph;
			l_product = l_pw * l_ph;
			
            /* update precision*/
			if (l_product > *p_max_prec) {
				*p_max_prec = l_product;
			}

		}
		++l_tccp;
		++l_img_comp;
	}
}
