Bug 416098

Summary: Cannot resume multi-page scan after scanner reconnect
Product: [Applications] Skanlite Reporter: Alexander Potashev <aspotashev>
Component: generalAssignee: Kåre Särs <kare.sars>
Status: REOPENED ---    
Severity: normal    
Priority: NOR    
Version First Reported In: 2.1.0.1   
Target Milestone: ---   
Platform: Fedora RPMs   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Alexander Potashev 2020-01-10 19:05:23 UTC 
SUMMARY
Cannot resume multi-page scan after scanner reconnect.

We had a power outage for 2-3 seconds after I scanned a few images in a row. However I want to scan a few more pages and continue the established sequence of file names. However on an attempt to just click "Scan" I get an error message "Invalid argument" titled "Skanlite Test".

The power outage resulted in a scanner reset, and the USB controller of my laptop probably detected device disconnect/connect cycle.

STEPS TO REPRODUCE
1. Configure Skanlite to only ask for file name once and then increment a sequence number in the file name.
2. Scan some pages in Skanlite
3. Unplug USB and/or turn off the scanner.
4. Plug in USB and/or turn on the scanner.
5. Click "Scan".

OBSERVED RESULT
Warning "Invalid argument", the page is not scanned.

EXPECTED RESULT
Should scan the new page.

SOFTWARE/OS VERSIONS
Operating System: Fedora 31
KDE Plasma Version: 5.17.4
KDE Frameworks Version: 5.64.0
Qt Version: 5.12.5
Kernel Version: 5.3.15-300.fc31.x86_64
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz
Memory: 15,4 ГиБ


ADDITIONAL INFORMATION
skanlite 2.1.0.1 on Fedora 31. Package: skanlite-2.1.0.1-3.fc31.x86_64
Comment 1 Kåre Särs 2020-01-10 20:56:06 UTC 
If you power off the scanner while Skanlite is running, I'm afraid it will not recover, because the sane-backend does not know what happened and your only choice is to restart Skanlite.

Restarting Skanlite in your situation should not be a problem as the sequence number is recalculated when you restart. It does not restart from 1 if there is a file already with that name.

Can you verify that actually happens?
Comment 2 Bug Janitor Service 2020-01-25 04:33:13 UTC 
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
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If you have already provided the requested information, please
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Thank you for helping us make KDE software even better for everyone!
Comment 3 Bug Janitor Service 2020-02-09 04:33:16 UTC 
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!
Comment 4 Alexander Potashev 2020-04-04 14:40:30 UTC 
(In reply to Kåre Särs from comment #1)
> Restarting Skanlite in your situation should not be a problem as the
> sequence number is recalculated when you restart. It does not restart from 1
> if there is a file already with that name.
> 
> Can you verify that actually happens?

I don't have physical access to a scanner at this time, cannot verify. Sorry. However restarting Skanlite seems like a workaround which requires extra steps from the user.

Can Skanlite may be reinitialize sane-backend in a case of an error?