diff --git a/third_party/agg23/agg_rasterizer_scanline_aa.cpp b/third_party/agg23/agg_rasterizer_scanline_aa.cpp index 46379f6..c6b3f01 100644 --- a/third_party/agg23/agg_rasterizer_scanline_aa.cpp +++ b/third_party/agg23/agg_rasterizer_scanline_aa.cpp @@ -48,6 +48,7 @@ //---------------------------------------------------------------------------- #include #include "agg_rasterizer_scanline_aa.h" +#include "third_party/base/numerics/safe_math.h" namespace agg { AGG_INLINE void cell_aa::set_cover(int c, int a) @@ -237,7 +238,7 @@ void outline_aa::render_line(int x1, int y1, int x2, int y2) int fy1 = y1 & poly_base_mask; int fy2 = y2 & poly_base_mask; int x_from, x_to; - int p, rem, mod, lift, delta, first, incr; + int rem, mod, lift, delta, first, incr; if(ey1 == ey2) { render_hline(ey1, x1, fy1, x2, fy2); return; @@ -268,16 +269,22 @@ void outline_aa::render_line(int x1, int y1, int x2, int y2) m_cur_cell.add_cover(delta, two_fx * delta); return; } - p = (poly_base_size - fy1) * dx; + pdfium::base::CheckedNumeric safeP = poly_base_size - fy1; + safeP *= dx; + if (!safeP.IsValid()) + return; first = poly_base_size; if(dy < 0) { - p = fy1 * dx; - first = 0; - incr = -1; - dy = -dy; + safeP = fy1; + safeP *= dx; + if (!safeP.IsValid()) + return; + first = 0; + incr = -1; + dy = -dy; } - delta = p / dy; - mod = p % dy; + delta = safeP.ValueOrDie() / dy; + mod = safeP.ValueOrDie() % dy; if(mod < 0) { delta--; mod += dy; @@ -287,12 +294,15 @@ void outline_aa::render_line(int x1, int y1, int x2, int y2) ey1 += incr; set_cur_cell(x_from >> poly_base_shift, ey1); if(ey1 != ey2) { - p = poly_base_size * dx; - lift = p / dy; - rem = p % dy; - if(rem < 0) { - lift--; - rem += dy; + safeP = static_cast(poly_base_size); + safeP *= dx; + if (!safeP.IsValid()) + return; + lift = safeP.ValueOrDie() / dy; + rem = safeP.ValueOrDie() % dy; + if (rem < 0) { + lift--; + rem += dy; } mod -= dy; while(ey1 != ey2) {