Comment 4 for bug 1029670

I decided to try reproducing it again a few times and gather some more data on it. Actually got a slightly different warning this time:

ant@Master-Ant:~$ simple-scan
*** glibc detected *** simple-scan: free(): invalid pointer: 0x00007fa300085240 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7e626)[0x7fa324db0626]
/usr/lib/sane/libsane-hpaio.so.1(sane_hpaio_close+0xa4)[0x7fa2fa132574]
/usr/lib/x86_64-linux-gnu/libsane.so.1(sane_dll_close+0x24)[0x7fa32585a864]
simple-scan[0x4229b9]
simple-scan[0x422a4a]
simple-scan[0x42367c]
/lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x699e5)[0x7fa325ac79e5]
/lib/x86_64-linux-gnu/libpthread.so.0(+0x7e9a)[0x7fa3250f6e9a]
/lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7fa324e244bd]

I've attached the full log of this from the terminal as 'crash' and whilst doing this, i was also running gdb with lot of dbgsym packages in the hopes of getting a decent backtrace.

Addtionally, info for the printer in use is as follows, from the log in the .cache folder in /home/:

DEBUG: scanner.vala:346: Device: name="hpaio:/usb/Photosmart_C4100_series?serial=MY7BDJ10KC04J7" vendor="Hewlett-Packard" model="Photosmart_C4100_series" type="all-in-one"
[+61.64s] DEBUG: simple-scan.vala:296: Requesting scan at 600 dpi from device 'hpaio:/usb/Photosmart_C4100_series?serial=MY7BDJ10KC04J7'
[+61.64s] DEBUG: scanner.vala:1491: Scanner.scan ("hpaio:/usb/Photosmart_C4100_series?serial=MY7BDJ10KC04J7", dpi=600, scan_mode=ScanMode.GRAY, depth=2, type=ScanType.SINGLE, paper_width=2100, paper_height=2970)

When this crash is reproduced, the log is always ended with:
[+80.52s] DEBUG: scanner.vala:1141: sane_start (page=0, pass=0) -> SANE_STATUS_DEVICE_BUSY
[+80.52s] WARNING: scanner.vala:1148: Unable to start device: Device busy
[+80.52s] DEBUG: scanner.vala:715: sane_cancel ()