Undefined array key 3 in ./inc/media.php on line 1700

[dregad]

The problem

My wiki's error log is swamped with hundreds of occurrences of the following errors, every day.

E_WARNING: Undefined array key 3 in ./inc/media.php(1700)
E_WARNING: Trying to access array offset on value of type null in ./inc/media.php(1700)

I was initially not able to reproduce the problem, so I searched the web server's logs for more information and found out that most of these requests seem to be triggered by bots; analyzing the queries, I realized that the problem occurs when an unknown or unaccessible namespace is referenced when opening the media manager with the following URL

http://example.com/dokuwiki/doku.php?do=media&ns=XXX

Where XXX is the offending namespace (e.g. from my logs: wiki:backup, which does not exist)

Version of DokuWiki

2024-02-06a Kaos (reproducible in master @ 31afae8)

PHP Version

8.2.16

Webserver and version of webserver

No response

Browser and version of browser, operating system running browser

No response

Additional environment information

No response

Relevant logs and/or error messages

No response

[dregad]

the problem occurs when an unknown or unaccessible namespace is referenced

This is not entirely true actually, something fishy is going on here...

Given the following namespaces hierarchy

+- root
   +- playground
   +- wiki

Accessing the URL http://example.com/dokuwiki/doku.php?do=media&ns=XXX

Value of XXX	Result	Comments
aaa	✅	Non-existing namespace aaa inserted before the first "real" namespace (playground)
zzz	❌	zzz namespace not listed in hierarchy, PHP warnings occur
qqq	✅	Non-existing namespace inserted between playground and wiki namespaces
playground	✅	playground namespace selected
playground:xxx	✅	Non-existing sub-namespace xxx inserted below playground
wiki:xxx	❌	Non-existing wiki:xxx namespace not listed in hierarchy, PHP warnings occur

[fiwswe]

2024-02-14a Kaos

Not very likely ;-) But let's assume you meant 2024-02-06a Kaos.

I can not reproduce this using:
$ curl --url 'https://<myhostname>/doku.php?do=media&ns=wiki:xyz'
where the namespace wiki:xyz does not exist. I also tried aaa and wiki:xxx (which also don't exist) with the same result. But I do have a more complicated hierarchy of namespaces in the wiki I was using.

DW: 2024-02-06a Kaos
PHP: 8.3.6 (using PHP-FPM)

So whatever is going on, must be still more obscure.

[dregad]

2024-02-14a Kaos

Not very likely ;-) But let's assume you meant 2024-02-06a Kaos.

Indeed. Sorry about that, fixed.

I can not reproduce this [...] But I do have a more complicated hierarchy of namespaces in the wiki I was using.

Do you have any namespaces after wiki (in lexicographical order) ? The key is the namespace specified by ns parameter, which must be higher than your last namespace's name (i.e. strcmp('XXX', 'yournamespace') > 0)

[dregad]

I think I've nailed it. I'll submit a pull request shortly.

[fiwswe]

Do you have any namespaces after wiki (in lexicographical order) ? The key is the namespace specified by ns parameter, which must be higher than your last namespace's name (i.e. strcmp('XXX', 'yournamespace') > 0)

No. I don't have any sub-namespaces in the wiki ns and my last root ns starts with a w So I tried the same thing with ns=xxx. Alas same result.

Note: I am seeing some unrelated warnings from the Discussion plugin which I have installed (not actively used except for a few test pages). I don't think these warnings have any bearing on your issue though.
PHP message: PHP Warning: Undefined array key "comment" in /dokuwiki/lib/plugins/discussion/action.php on line 222

[dregad]

I don't know what to say. This is consistently reproducible for me, with a fresh install of DokuWiki from Git master, with every plugin disabled.

[dregad]

OK let me rephrase that.

With master branch, I get the PHP warnings, but the temporary namespace is added.

I was actually testing with a commit fixing the PHP warning that started this whole thing (adding an array_key_exists() check to the while loop in media_nstree()). In this case, no more warnings but the temp namespace is gone.