2019-07-23 18:47:42     mje__   I have a strange warning that I cannot provide a runnable example for. The code "if (defined($match->{in_control}) && ($match->{in_control} == 1))" ends up issuing a warning saying "Use of uninitialized value in numeric eq (==)" but I cannor understand how this can happen. $match is defined and even if it wasn't I'd expect a warning saying trying to deref and undef. I don't think it is autovivification as my tests show 
2019-07-23 18:47:42     mje__   defined doesn't do this. Any ideas?
2019-07-23 18:48:44     mje__   Perl 5.24.4
2019-07-23 18:56:48     alh     in_control could have operator overloading
2019-07-23 18:57:00     alh     Alternatively, the warning isn't happening where you think it is which seems more likely
2019-07-23 18:57:21     alh     Line numbers can be wrong if it's part of a giant if () { } elsif () { } else {} block
2019-07-23 18:57:35     alh     So it could be a different conditional triggering it
2019-07-23 18:58:54     mje__   Simple hash ref, so no overloading. The warning seems pretty good since the line mentioned contains an ==
2019-07-23 18:59:58     alh     Is it part of a multi-line conditional?
2019-07-23 19:00:02     alh     Can you show us more of the code
2019-07-23 19:00:08     mst     the warning is happening somewhere else
2019-07-23 19:00:10     mst     99% chance
2019-07-23 19:02:28     mje__   Here is what it looks like now https://pastebin.com/fsTnLRaS, the only thing changed from when the warning was output was defined changed to exists
2019-07-23 19:02:29     Repaster        Repasted text from mje__: http://perl.bot/p/mmydbc
2019-07-23 19:03:03     alh     That's using exists
2019-07-23 19:03:04     alh     not defined
2019-07-23 19:03:07     alh     So it can exist and e undef
2019-07-23 19:03:13     alh     Which is your problem
2019-07-23 19:03:46     mje__   I said, the original was defined when the warning was issued and what I pasted was afterwards when it was changed to exists
2019-07-23 19:04:48     mje__   the change from defined to exists is likely wrong but the warning came from the defined case
2019-07-23 19:06:29     alh     Can you show more context?
2019-07-23 19:12:38     mje__   https://pastebin.com/sYC3XR31
2019-07-23 19:12:39     Repaster        Repasted text from mje__: http://perl.bot/p/t8p5x4
2019-07-23 19:16:48     alh     before line 18 warn the value of $existing_match->{in_control}
2019-07-23 19:17:01     alh     Beore line 14 do the same for $events{$event_id}->{event_status_id} 
2019-07-23 19:17:05     alh     That may be where the real warning is coming from
2019-07-23 19:22:02     mje__   ok, so the crux of the opinion is the line number is possibly wrong and so other == tests could be at fault?
2019-07-23 19:24:47     mst     the crux of the opinion is "you're confused about *something*
2019-07-23 19:24:51     alh     Yes. And you can figure out by adding debug everywhere
2019-07-23 19:24:57     mst     I'd probably apply warn + Data::Dumper
2019-07-23 19:25:12     alh     If you think $x->{foo} == 1 is warning, warn reight before that conditional, warn inside that conditional, warn after that conditional
2019-07-23 19:25:31     alh     Where the unintialized value warning appears in regards to what you've added should help you track it down
2019-07-23 19:28:21     Grinnz  source filters are also known to screw up line numbers
2019-07-23 19:29:32     mst     oh. yes. if you have 'use Switch;' in that code, you can assume all line numbers are wrong
2019-07-23 19:30:00     Grinnz  (and in that case, that it also caused the error)
2019-07-23 19:31:00     mje__   Unfortunately this is code working on live data and although it is possible to play it back the playback isn't EXACTLY as it was live. We don't use Switch. I hadn't considered the warning line number was wrong so I've got something to work on. Thanks
2019-07-23 19:31:43     Grinnz  there are still some core bugs that make wrong line numbers too
2019-07-23 19:34:35     alh     Also if a comment like this is anywhere in the file:
2019-07-23 19:34:38     alh     # line 5 10
2019-07-23 19:35:07     alh     Or even:
2019-07-23 19:35:09     alh     # line 10
2019-07-23 19:35:12     mst     honestly I still thing you're just confused about the data