crash: index 54 out of range for slice of length 48

[matthiaskrgr]

file: https://github.com/FLIF-hub/benchmarks/blob/master/test_animations/random-gifs/SteamEngine.png

Processing: ./test_animations/random-gifs/SteamEngine.png
    320x240 pixels, PNG format
    8 bits/pixel, 16 colors in palette
    IDAT size = 2761 bytes
    File size = 38713 bytes
Reducing image to 4 bits/pixel, 15 colors in palette
Trying: 8 combinations
Found better combination:
    zc = 9  zm = 9  zs = 0  f = 0        2457 bytes
    IDAT size = 2457 bytes (304 bytes decrease)
    file size = 3868 bytes (34845 bytes = 90.01% decrease)
thread 'main' panicked at 'index 54 out of range for slice of length 48', /checkout/src/libcore/slice/mod.rs:748:4
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
             at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::_print
             at /checkout/src/libstd/sys_common/backtrace.rs:71
   2: std::panicking::default_hook::{{closure}}
             at /checkout/src/libstd/sys_common/backtrace.rs:60
             at /checkout/src/libstd/panicking.rs:381
   3: std::panicking::default_hook
             at /checkout/src/libstd/panicking.rs:397
   4: std::panicking::rust_panic_with_hook
             at /checkout/src/libstd/panicking.rs:577
   5: std::panicking::begin_panic
             at /checkout/src/libstd/panicking.rs:538
   6: std::panicking::begin_panic_fmt
             at /checkout/src/libstd/panicking.rs:522
   7: rust_begin_unwind
             at /checkout/src/libstd/panicking.rs:498
   8: core::panicking::panic_fmt
             at /checkout/src/libcore/panicking.rs:71
   9: core::slice::slice_index_len_fail
             at /checkout/src/libcore/slice/mod.rs:748
  10: png::decoder::expand_paletted
             at /checkout/src/libcore/slice/mod.rs:879
             at /checkout/src/libcore/slice/mod.rs:730
             at /checkout/src/liballoc/vec.rs:1575
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/png-0.9.0/src/decoder/mod.rs:455
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/png-0.9.0/src/utils.rs:33
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/png-0.9.0/src/decoder/mod.rs:452
  11: <png::decoder::Reader<R>>::next_interlaced_row
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/png-0.9.0/src/decoder/mod.rs:273
  12: oxipng::optimize_png
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/png-0.9.0/src/decoder/mod.rs:238
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/png-0.9.0/src/decoder/mod.rs:229
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/image-0.15.0/./src/png.rs:84
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/image-0.15.0/./src/dynimage.rs:470
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/image-0.15.0/./src/dynimage.rs:622
             at /home/matthias/.cargo/registry/src/github.com-1ecc6299db9ec823/image-0.15.0/./src/dynimage.rs:672
             at src/lib.rs:626
  13: oxipng::optimize
             at src/lib.rs:302
  14: oxipng::handle_optimization
             at src/main.rs:267
  15: oxipng::main
             at src/main.rs:234
  16: __rust_maybe_catch_panic
             at /checkout/src/libpanic_unwind/lib.rs:99
  17: std::rt::lang_start
             at /checkout/src/libstd/panicking.rs:459
             at /checkout/src/libstd/panic.rs:361
             at /checkout/src/libstd/rt.rs:59
  18: __libc_start_main
  19: _start

[shssoichiro]

Is this an APNG file? Oxipng doesn't currently support animated PNGs (see #79). Perhaps Oxipng should show a more helpful error message on detecting an APNG file, until APNG support is implemented.

[matthiaskrgr]

Hmm, I wondered too.
When I crushed the bouncing ball apng from another ticket, oxipng exited more gracefully "The resulting image is corrupted and will not be outputted.", so I assumed that apngs were handled.
However this was not the case here and it crashed so I made the ticket just in case.