Last modified: 2014-11-12 17:28:52 UTC

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Bug 50107 - Variable added_lines is now an array instead of a string
Variable added_lines is now an array instead of a string
Status: NEW
Product: MediaWiki extensions
Classification: Unclassified
AbuseFilter (Other open bugs)
All All
: Normal major (vote)
: ---
Assigned To: Nobody - You can work on this!
: code-update-regression
Depends on:
Blocks: documentation
  Show dependency treegraph
Reported: 2013-06-24 15:40 UTC by Helder
Modified: 2014-11-12 17:28 UTC (History)
6 users (show)

See Also:
Web browser: ---
Mobile Platform: ---
Assignee Huggle Beta Tester: ---


Description Helder 2013-06-24 15:40:23 UTC
1. Create a page with "{{this is}}"
2. Edit the page and replace its content by "*THIS IS A BUG ON ABUSE FILTER!":
3. Open [[Special:AbuseFilter/test]], which in my case was
4. Type
length(added_lines) <= 2 & contains_any( added_lines, "THIS IS A BUG" )
5. Click "Test" and bang! The edit is detected! If it is of any help, here is the link provided to "examine" the edit:"THIS+IS+A+BUG"+%29%0A&uselang=en

The filter shouldn't detect it, because "added_lines" obviously has a lot more than 2 characters. Nonetheless, if I replace "<= 2" by "== 1" it is still detected.

How can a string of 31 characters have length 1? This is plain wrong...
Comment 1 Helder 2013-06-25 13:07:12 UTC
Ok, so I made one more test at
and used Special:AbuseFilter/test to check the following filter:
length(added_lines) == 3 & contains_any( added_lines, "Lorem" )
and the edit was detected.

It seems abuse filter's "added_lines" is an array and then "length(added_lines)" is the number of items on this array.

Such a behavior is not documented at
and it is not obvious from

that the value of "added_lines" is an array (not an string).
Comment 2 Helder 2013-07-03 15:17:39 UTC
A similar problem happens when I use "user_groups":
For a user , 

The test
"confirmed" in user_groups
matches a user which is in the group "autoconfirmed" but **not** in the group "confirmed". But the documentation[1] says "in" applies only to "strings", so why when I execute
I also get a match? (the user in question is in exactly 4 groups)

If "user_groups" is a string, its length should be at least the length of "confirmed" (which is 9), not 4.

Comment 3 Helder 2013-07-05 16:21:30 UTC
Here is another test which returns 1 (which means "true"):

(list:= ["a", "b", "c"];) & contains_any(list,"a\n")

I think the real bug is we have no documentation about these variables being arrays and how they are converted to strings (notice the "\n" in the above example).
Comment 5 Helder 2013-07-14 19:51:36 UTC
According to
the variable "added_lines" was changed to an array somewhere from 13 February 2013 and as such "length (added_lines)" now gets the number of rows, and this changed the conditions under which existing filters were triggered.
Comment 6 Helder 2013-07-14 20:07:22 UTC
Is this working like this since 2009??? I found the following on r49221:
* Use lists instead of implode()d strings in built-in variables wherever it's possible

ATTENTION! This may break filters that rely on "added_lines contains 'bla-bla'" syntax. They'll need to be replaced with "string(added_lines) contains 'bla-bla'"
Comment 7 Andre Klapper 2013-07-15 10:50:28 UTC
No need for "[regression]" in subject if you also set the keyword.
However, not sure if I would call it a regression if it's been like this for four years.
Comment 8 Helder 2013-07-15 17:48:14 UTC
Another example of the confusion caused by this (from 17 June 2009):
* [[Special:AbuseFilter/history/172/diff/prev/2121]]
* [[Wikipedia talk:Edit filter/Archive 3#Filter stopped working - strange testing results ..]]
Comment 9 Jesús Martínez Novo (Ciencia Al Poder) 2013-08-16 13:12:34 UTC
See also:

(added and documented by Helder)
Comment 10 Jesús Martínez Novo (Ciencia Al Poder) 2013-08-16 13:13:13 UTC
(In reply to comment #9)
> See also:
> (added and documented by Helder)

Whoops, ignore that, wrong bug!

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