# Having to wait 10 minutes counts as a major effect on usability Control: severity -1 important On Sat, Jun 14, 2014 at 12:16:27PM +0100, Olly Betts wrote:
On Fri, Jun 13, 2014 at 11:15:26AM +0100, Wookey wrote:
+++ Jenny Black [2014-06-11 19:12 +1200]:
Olly has just had a look (thank you Olly!), and in xtherion he changed: set rx {\S*[^\]\s]\s+\[\d+\]} to: set rx {\s\[\d+\]} It now no longer hangs, and runs as well as ever. We're not sure what the regular expression search was for, or whether changing it matters. As far as I can see it doesn't, as the pdf and log files have already been made.
Just noticed this. Well fettled. I've filed a bug in Debian BTS about this so it doesn't get forgotten.
I'll do a 5.3.15 upload with this and ol's other fixes in very soon.
I'm not at all confident this fix is correct - my grasp of Tcl is insufficient to understand what the code is actually doing with this regex.
All I did was to prune the bit off the start of the pattern which was causing the regex engine to do insane amount of backtracking (which with a large log file could easily result in it taking 10 minutes to run this regex over the whole log).
So you might want to wait for comments from Stacho or Martin before shipping this.
After staring some more, I'm fairly sure my patch doesn't actually constitute a fix (it was never really intended to - I just meant it to show what was taking all the time). But it would be good to fix this before the Debian release freeze, so in the absence of any clues as to what this code is trying to do (as far as I can make out so far, it seems to be parsing a log to get a list of errors to show), I'll sit down with the tcl docs and figure it out. Cheers, Olly