kousu
commented
5 years ago I traced what zxing and you are doing differently.
You're calling decodeMultiple():
they're only calling that if you pass --search-multi:
Indeed, I can reproduce the exact same crash. It's bizarre; I don't read asm that well but it looks like my compiler hard-coded %rdi=*(0x18), followed by `%rdi==*(0x20), which is impossible since 0x18 and 0x20 are obviously a special off-limits memory address, just like the error ("Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000018") says.
$ lldb -- zxing --more --search-multi code.png
(lldb) target create "zxing"
Current executable set to 'zxing' (x86_64).
(lldb) settings set -- target.run-args "--more" "--search-multi" "code.png"
(lldb) run
Process 14786 launched: '/usr/local/bin/zxing' (x86_64)
Process 14786 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x18)
frame #0: 0x00000001000483af zxing`zxing::multi::GenericMultipleBarcodeReader::translateResultPoints(zxing::Ref<zxing::Result>, int, int) + 249
zxing`zxing::multi::GenericMultipleBarcodeReader::translateResultPoints:
-> 0x1000483af <+249>: movq 0x18, %rdi
0x1000483b7 <+257>: cmpq 0x20, %rdi
0x1000483bf <+265>: je 0x1000483dc ; <+294>
0x1000483c1 <+267>: movq $0x0, (%rdi)
Target 0: (zxing) stopped.
(lldb) 
lubo
I'm getting a segfault with zxinglight every time it successfully parses a QR code.
Here's a test script that reproduces the crash:
and an image that triggers it:
and an image that does not trigger it.
It seems that something is glitching on munging the zxing-cpp result back into python.
Here is the backtrace in full gory Apple detail:
It's something specific to zxinglight because the zxing binary can handle this image fine:
Furthermore, this happens for me even with your tests. (yay tests!)