ExamDiff Pro Locks up Windows 2000 forcing a power-off

AndyP · Post by **AndyP** » Tue Oct 26, 2004 5:26 am

First of all you won't believe the fun I had finding this out and then tracing the problem back to Exam Diff Pro.

I'm comparing two 911Kb text files, I've selected the two files in explorer and done a "Compare" (right-click menu item). Exam Diff Pro starts up and correctly shows me the two files along with all the differences.

All well and good.

Now I go to any difference using the scroll bars and (as the files have about 3000 lines, some 7000+ characters) I scroll around for a bit finding the characters that are different.

Machine locks up completely (as in music I have playing in iTunes stops, mouse stops moving, keyboard caps lock on/off no longer changes the little light on the keyboard) and I have to power off and re-start.

It's not the same files, the same difference, it just happens after I try scrolling around for about 20 seconds.

Now this is a company machine I can use for weeks without having to re-boot, and these lock ups have only happened running Exam Diff Pro. Nothing else seems to cause it (well, I've been here 2 years and it's the first bit of software that's done it).

It happens *every* time I use Exam Diff Pro.

So, my question is this .... Is anyone else successfully comparing files with these dimensions (i.e. 7000 x 3000 characters)?

Oddly, this problem doesn't happen with the "Free" version of Exam Diff so it must be something "pro" related. My best guess would be the fact that the Pro version highlights the "different" characters on the line and the basic one doesn't.

So, any ideas?

Andy Pellew

AndyP · Post by **AndyP** » Tue Oct 26, 2004 5:40 am

Ok,

I just tried it out on a small file (9 lines) which had each line 7455 characters long. First of all I copied the file so I had two identical copies, ran Exam Diff Pro and it reported that the files were the same, I scrolled back and forth (for about 30 seconds) and nothing happened.

I then changed the final character of one of the lines in one of the files and went back into exam diff pro. It correctly highlighted the difference, I scrolled back and forth again for about another 20 seconds and everything locked up and it was reboot time again.

So, *length* of the file seems to mean nothing, and neither does length of each line, it appears to only be a problem when there is a difference in a long line is displayed.

Looks like a memory leak to me ...

Help?

AndyP

Post by **psguru** » Tue Oct 26, 2004 5:40 am

Is there a way for you to (privately) send me your files that cause the lock-up, along with your options (exported to a file via Options | Export to File button)?

BTW, are you using the latest (3.2c) version? Also, when your machine locks up, can you Ctrl+Alt+Del, start the Task Manager, and kill EDP?

AndyP · Post by **AndyP** » Tue Oct 26, 2004 6:05 am

psguru wrote:Is there a way for you to (privately) send me your files that cause the lock-up, along with your options (exported to a file via Options | Export to File button)?

BTW, are you using the latest (3.2c) version? Also, when your machine locks up, can you Ctrl+Alt+Del, start the Task Manager, and kill EDP?

I purchased the software about 2 weeks ago so it must be the latest version, and I can e-mail you the two files I used in the above (second) test ... My e-mail address is [deleted]. Can you e-mail me and I'll reply.

It's a complete lockup, Ctrl+Alt+Del doesn't work.

Thanks.

AndyP

Post by **psguru** » Tue Oct 26, 2004 5:22 pm

Thanks, I got your files. While I couldn't reproduce locking-up Windows, drawing of long lines, especially if they have tabs, is computationally-expensive in the current drawing algorithm in EDP. We'll try to optimize the algorithm in the next public build.

Thanks again for reporting the issue.