Calculate JPEG2000 total_component_width for each tile in isolation

[radarhere]

Within j2k_decode_entry, total_component_width is initialized before the loop through tiles, and is never reset.

Pillow/src/libImaging/Jpeg2KDecode.c

Line 648 in 2d18dac

int total_component_width = 0;

Pillow/src/libImaging/Jpeg2KDecode.c

Lines 787 to 789 in 2d18dac

	/* Decode the image tile-by-tile; this means we only need use as much
	memory as is required for one tile's worth of components. */
	for (;;) {

Pillow/src/libImaging/Jpeg2KDecode.c

Line 858 in 2d18dac

total_component_width += csize;

This means that the value used in

Pillow/src/libImaging/Jpeg2KDecode.c

Line 869 in 2d18dac

tile_bytes = tile_width * tile_height * total_component_width;

just keeps growing.

Instead, it should be set to zero within the tile loop, so it is only considering the current tile.