Unexpected encoding / conversion of query string

[gesinn-it-gea]

The Page Forms extension page on mediawiki.org gives the following advice:

Note that if any part of your query string — such as a page name or anything else — contains characters such as apostrophes ('), ampersands (&), or plus signs (+), you will need to URL-encode that value. For that, you can use the urlencode function from the ParserFunctions extension. The example above, for instance, would need to change to: Quote[Author]={{urlencode:{{PAGENAME}}}}.}}

Following the above advice using query string=Template[Field]={{urlencode:Test String}} leads to Test+String being displayed in the form field.

Summary:
MW 1.35.8
PF 5.5.1

1. {{urlencode:Test String}} → Test+String
2. {{urlencode:Test_String}} → Test_String
3. {{urlencode:Test String&ampersand}} → Test+String&ampersand
4. Test String → Test String
5. Test_String → Test_String
6. Test String&ampersand → Test String

This leaves the user with no working combination for all cases.

[krabina]

There is also {{PAGENAMEE}} btw.

[krabina]

What about {{urlencode:Test String|WIKI}}?

[gesinn-it-gea]

The following commit introduced this breaking change. Before, it was working with default {{urlencode}}.

wikimedia@d29c9f3#diff-31f9c3daecfcc90f5f898ed2e119979d92c59785d26dbac658845c2199067bbc

$queryString = str_replace( '+', '%2B', $queryString ); // prevent decoding + to space character

This change is related to #autoedit Modifying a list of values

[gesinn-it-gea]

7) {{urlencode:Test String|PATH}} → Test String
8) {{urlencode:Test_String|PATH}} → Test_String
9) {{urlencode:Test String&ampersand|PATH}} → Test String&ampersand
10) {{urlencode:Test String+plus|PATH}} → Test String+plus

Using option PATH seems to work. This option is not MW default and requires users to modify existing query strings.

Conclusion: this was a breaking change not marked as such.

[gesinn-it-gea]

A comparison between the different encodings can be found here: https://www.mediawiki.org/wiki/Manual:PAGENAMEE_encoding#Encodings_compared