set-alias-page.py generates misleading pages

[acuteenvy]

The get_alias_page function doesn't do its job properly. This script then works on non-alias pages, and subsequently makes a huge mess by generating misleading pages. It also has some issues with page titles that contain spaces.

Examples: #11365.
Previous runs of this script:

• pages/*: add standard translation and links #11331, reverted in Revert "pages/*: add standard translation and links (#11331)" #11374,
• pages.*: add standard translation #9672 not reverted, some pages are affected

set-alias-page.py should not be used until this is fixed.

[sebastiaanspeck]

We could add a warning in the script to make people aware of this issue. Only mentioning here that the script should not be used, is too less visible for others

[sebastiaanspeck]

We could add a warning in the script to make people aware of this issue. Only mentioning here that the script should not be used, is too less visible for others

I see that It already has a warning at the top of the script:

Disclaimer: This script generates a lot of false positives so it
isn't suggested to use the sync option. If used, only stage changes
and commit verified changes for your language.