Special pages that return no results get evaluated as true when transcluded
Open, Needs TriagePublicBUG REPORT
Actions

Assigned To

None

Authored By

	Sophivorus
	May 29 2019, 5:34 PM

Description

Create a new page with the following content:

{{#if:{{Special:WhatLinksHere/{{FULLPAGENAME}}}}|1|0}}

If the page has no incoming links, then we would expect to see 0. However, we get 1.

Here is a demo.

Same thing happens with Special:RelatedChanges (see the demo) so I infer it's not specific to any one special page.

Related Objects

Mentioned In: T285609: Special pages lists: transclusion in ParserFunctions
Mentioned Here: T285609: Special pages lists: transclusion in ParserFunctions

Event Timeline

Sophivorus created this task.May 29 2019, 5:34 PM

Restricted Application added subscribers: Liuxinyu970226, Aklapper. · View Herald TranscriptMay 29 2019, 5:34 PM

Sophivorus added projects: ParserFunctions, MediaWiki-Special-pages, MediaWiki-Parser.May 29 2019, 5:34 PM

Sophivorus updated the task description. (Show Details)

Sophivorus updated the task description. (Show Details)May 29 2019, 5:42 PM

Sophivorus updated the task description. (Show Details)May 29 2019, 5:44 PM

Sophivorus updated the task description. (Show Details)

Strange thing is that the transclusions seem to be returning an empty string as expected (see the div at the bottom of the demo) so maybe the issue is related to parsing order.

Sophivorus renamed this task from Transcluding special pages that return no results, gets evaluated as true to Special pages that return no results get evaluated as true when transcluded.May 30 2019, 3:02 PM

Krinkle moved this task from To triage to SpecialPage system on the MediaWiki-Special-pages board.Jun 24 2019, 3:51 PM

Umherirrender mentioned this in T285609: Special pages lists: transclusion in ParserFunctions.Jun 29 2021, 2:52 PM

Aklapper merged a task: T285609: Special pages lists: transclusion in ParserFunctions.Jun 29 2021, 4:04 PM

Aklapper added subscribers: Shalomori123, Umherirrender.

According to what I wrote in T285609 I think that the problem is connected to the function "insertStripItem()" in:
https://gerrit.wikimedia.org/g/mediawiki/core/+/refs/heads/master/includes/parser/Parser.php#1340
Because: