double free or corruption (!prev) with avx2

[wwww-wwww]

imagedata.zip width 460 height 460 num_channels 4 bytes_per_channel 1

[animetosho]

Ack, looks like I messed up the alignment code.

You can fix this by changing the following line in fpnge.cc:

std::vector<unsigned char> pdata_buf(bytes_per_line_buf);

and replacing it with

std::vector<unsigned char> pdata_buf(bytes_per_line_buf + SIMD_WIDTH - 1);

Thanks for reporting!