Possible viewer bug?

itimpi · 05-13-2014, 04:01 AM

I ran a library check today and came across some anomalous behaviour that looks like it may be a viewer bug?

I was investigating extra book formats that had been reported. In Calibre I went to the book in question which said there should be an epub and mobi format files and pressed the 'Click to Open' option to go the books folder. There were 3 ebook files there:

Code:

The Third Science Fiction Megap - Various.epub
The Third Science Fiction Megapack - Various.epub
The Third Science Fiction Megapack - Various.mobi

As an extra epub file had been reported I assumed that it was the first one and I deleted it. As a check that I had deleted the correct file, I then selected the option to view a specific format and selected epub. The book appeared to come up in the viewer fine. I then simply exited the viewer. On checking the first file had re-appeared!

On slightly different issue relating to how the Library Maintenance runs I have set it to ignore files called 'c2o_thumbnail.jpg' or 'c2o_resizedcover.jpg' as I use Calibre2opds and it can store its cover and thumbnail image files with each book (also could I have used c2o_*.* as a shorthand for these files?). Despite that I was given a long list of files with these names with the error statement 'Unknown files in books'. Should these not have been ignored?

Should I raise either of these as a formal bug report?

BTW: I am running Calibre 1.36 on Windows

BetterRed · 05-13-2014, 04:36 AM

@itimpi - First one looks like it might be a path length issue - but why would the viewer be creating any files in the library book folders anyway!

BR

itimpi · 05-13-2014, 04:44 AM

Quote:

Originally Posted by BetterRed

@itimpi - First one looks like it might be a path length issue - but why would the viewer be creating any files in the library book folders anyway!

BR

I agree - which is why I thought the bug must be in the viewer rather than the main Calibre program. However I guess it could be created by Calibre before launching the viewer.

Normally I would not notice such behaviour as I avoid browsing the Calibre filestore unnecessarily. However in this case I was doing so because I was trying to resolve the issues reported by Library maintenance.

DoctorOhh · 05-13-2014, 04:53 AM

Quote:

Originally Posted by itimpi

I agree - which is why I thought the bug must be in the viewer rather than the main Calibre program. However I guess it could be created by Calibre before launching the viewer.

Normally I would not notice such behaviour as I avoid browsing the Calibre filestore unnecessarily. However in this case I was doing so because I was trying to resolve the issues reported by Library maintenance.

Do you have the viewer set to save the last read position? If so after inserting the bookmark file maybe something is happening upon repacking.

itimpi · 05-13-2014, 05:11 AM

Quote:

Originally Posted by DoctorOhh

Do you have the viewer set to save the last read position? If so after inserting the bookmark file maybe something is happening upon repacking.

On looking in the preferences I do not think so (although I could have been looking at the wrong setting).

All settings should be a defaults as I only use the viewer for quick checks - not for normal reading.

Whatever the cause it suggests a mismatch between the maximum path lengths being used by the viewer and the main Calibre program.

BetterRed · 05-13-2014, 05:20 AM

Quote:

Originally Posted by itimpi

On looking in the preferences I do not think so (although I could have been looking at the wrong setting).

All settings should be a defaults as I only use the viewer for quick checks - not for normal reading.

Whatever the cause it suggests a mismatch between the maximum path lengths being used by the viewer and the main Calibre program.

@itimpi See attachment for the setting

Oh, and bookmarking will cause file to be written.

BR

itimpi · 05-13-2014, 05:42 AM

That is the setting I checked and it is not set.

I did not get a chance to do any bookmarking. I simply opened the book, viewed the cover and closed the book.

All a bit puzzling at the moment

kovidgoyal · 05-13-2014, 06:33 AM

And is this repeatable. That is if you delete that file and rerun the viewer does the file re-appear? Nake sure that the file is actually deleted by eyeballing the folder in windwos explorer. The viewer does not write to the original file unless it is set to remember the current page when quitting. It does not however, alter its filename in anyway.

itimpi · 05-13-2014, 06:48 AM

Quote:

Originally Posted by kovidgoyal

And is this repeatable. That is if you delete that file and rerun the viewer does the file re-appear? Nake sure that the file is actually deleted by eyeballing the folder in windwos explorer. The viewer does not write to the original file unless it is set to remember the current page when quitting. It does not however, alter its filename in anyway.

Yes - it is definitely repeatable. I currently have two books I have found exhibiting this behaviour. As you say the viewer is not expected to write a file in normal use so it is definitely puzzling behaviour.

I have checked and the option to remember the current page is NOT set. I actually tried the option to restore defaults (which set it so the default is to have it set), applied that, and then unchecked it again and applied that. I wonder if there is any other setting that can cause this behaviour?

The new ebook file appears as soon as I click to view the book as epub (before the viewer has managed to display the contents). I do not get any new book file appear if I elect to view the mobi format file I also have (as I expected would be the case).

Is there anything else I can do to try and get you some diagnostics to pin down why it is happening?

kovidgoyal · 05-13-2014, 06:54 AM

Try disabling the internal viewer via Preferences->Behavior and see if it happens happens with some other viewer. That will tell us if the problem is in the viewer or elsewhere.

BetterRed · 05-13-2014, 07:03 AM

Another thought - convert the The Third Science Fiction Megapack - Various.epub EPUB to say AZW3 - what file name do you get for the AZW3?

BR

itimpi · 05-13-2014, 07:21 AM

Quote:

Originally Posted by kovidgoyal

Try disabling the internal viewer via Preferences->Behavior and see if it happens happens with some other viewer. That will tell us if the problem is in the viewer or elsewhere.

I did this. I had to change the Windows file assoications as I hd them set to use the Viewer as well for ePub. I actually set it instead to open in TextPad (which is not really an ebook viewer but could load the file). The anomalous file was still created so it looks like it is the main Calibre program creating it and not the viewer.

kovidgoyal · 05-13-2014, 07:32 AM

The only way this can happen is if the longer path is too long for windows, which will causes calibre to be unable to read that file. When that happens, calibre will look for files of the same format in the directory and use the first one it finds, automatically copying it to the correct filename.

You shoudl be able to fix it by simply renaming the author/title to something short and then naming it back.

There was a bug in the pre 1.0 version of calibre that could end up creating files that were too long for windows in some corner cases, that bug has now been fixed.

itimpi · 05-13-2014, 08:57 AM

Quote:

Originally Posted by kovidgoyal

The only way this can happen is if the longer path is too long for windows, which will causes calibre to be unable to read that file. When that happens, calibre will look for files of the same format in the directory and use the first one it finds, automatically copying it to the correct filename.

The strange thing is that it found the one that was apparently 'too long'.

The path name was not very long - the total path before renaming being

Code:

W:\eBOOKS\CalibreLibrary\Various\The Third Science Fiction MegaPack (22827)\The Third Science Fiction MegaP.epub

This has now been shortened to

Code:

W:\eBOOKS\CalibreLibrary\Various\The Third Science Fiction MegaPack (22827)\The Third Science Fiction MegaP.epub

This is shorter, but I would assume that the previous one was well within Windows limits. Just a suggestion - could the library maintenance function have identified this as a possible problem case?

Quote:

You shoudl be able to fix it by simply renaming the author/title to something short and then naming it back.

That worked - thanks very much.

At least I now know what to do if I encounter it again.

kovidgoyal · 05-13-2014, 09:08 AM

It wont happen again, this is the result of a historical bug that has been fixed since 1.0 was released.

I will look into adding a check for it in check library, unfortunately, i am rather swamped at the moment.

05-13-2014, 04:01 AM	#1
itimpi Wizard Posts: 4,552 Karma: 950151 Join Date: Nov 2008 Device: Sony PRS-950, iphone/ipad (Marvin/iBooks/QuickReader)	Possible viewer bug? I ran a library check today and came across some anomalous behaviour that looks like it may be a viewer bug? I was investigating extra book formats that had been reported. In Calibre I went to the book in question which said there should be an epub and mobi format files and pressed the 'Click to Open' option to go the books folder. There were 3 ebook files there: Code: The Third Science Fiction Megap - Various.epub The Third Science Fiction Megapack - Various.epub The Third Science Fiction Megapack - Various.mobi As an extra epub file had been reported I assumed that it was the first one and I deleted it. As a check that I had deleted the correct file, I then selected the option to view a specific format and selected epub. The book appeared to come up in the viewer fine. I then simply exited the viewer. On checking the first file had re-appeared! On slightly different issue relating to how the Library Maintenance runs I have set it to ignore files called 'c2o_thumbnail.jpg' or 'c2o_resizedcover.jpg' as I use Calibre2opds and it can store its cover and thumbnail image files with each book (also could I have used c2o_. as a shorthand for these files?). Despite that I was given a long list of files with these names with the error statement 'Unknown files in books'. Should these not have been ignored? Should I raise either of these as a formal bug report? BTW: I am running Calibre 1.36 on Windows

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05-13-2014, 04:36 AM	#2
BetterRed null operator (he/him) Posts: 20,575 Karma: 26954694 Join Date: Mar 2012 Location: Sydney Australia Device: none	@itimpi - First one looks like it might be a path length issue - but why would the viewer be creating any files in the library book folders anyway! BR

05-13-2014, 05:42 AM	#7
itimpi Wizard Posts: 4,552 Karma: 950151 Join Date: Nov 2008 Device: Sony PRS-950, iphone/ipad (Marvin/iBooks/QuickReader)	That is the setting I checked and it is not set. I did not get a chance to do any bookmarking. I simply opened the book, viewed the cover and closed the book. All a bit puzzling at the moment

05-13-2014, 06:33 AM	#8
kovidgoyal creator of calibre Posts: 43,860 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	And is this repeatable. That is if you delete that file and rerun the viewer does the file re-appear? Nake sure that the file is actually deleted by eyeballing the folder in windwos explorer. The viewer does not write to the original file unless it is set to remember the current page when quitting. It does not however, alter its filename in anyway.

05-13-2014, 06:54 AM	#10
kovidgoyal creator of calibre Posts: 43,860 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Try disabling the internal viewer via Preferences->Behavior and see if it happens happens with some other viewer. That will tell us if the problem is in the viewer or elsewhere.

05-13-2014, 07:03 AM	#11
BetterRed null operator (he/him) Posts: 20,575 Karma: 26954694 Join Date: Mar 2012 Location: Sydney Australia Device: none	Another thought - convert the The Third Science Fiction Megapack - Various.epub EPUB to say AZW3 - what file name do you get for the AZW3? BR

05-13-2014, 07:32 AM	#13
kovidgoyal creator of calibre Posts: 43,860 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	The only way this can happen is if the longer path is too long for windows, which will causes calibre to be unable to read that file. When that happens, calibre will look for files of the same format in the directory and use the first one it finds, automatically copying it to the correct filename. You shoudl be able to fix it by simply renaming the author/title to something short and then naming it back. There was a bug in the pre 1.0 version of calibre that could end up creating files that were too long for windows in some corner cases, that bug has now been fixed.

05-13-2014, 09:08 AM	#15
kovidgoyal creator of calibre Posts: 43,860 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	It wont happen again, this is the result of a historical bug that has been fixed since 1.0 was released. I will look into adding a check for it in check library, unfortunately, i am rather swamped at the moment.

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