is_front_page flag affected by frontpage ID and page Title strange conflict

[m_i_n]

I want to report a strange bug. The is_front_page flag has incorrect value in cases like described below:

Front page in Settings / Reading is set to a static page: ​http://i.imgur.com/DzrbOVM.png
This Sample Page ID is 2
If you visit any other page, all is fine. For example the Lorem ipsum page: ​http://i.imgur.com/n5M0x8R.png
However, if you change title of this page to be the same as ID of a frontpage - in my case 2, then the is_front_page flag changes value to incorrect: ​http://i.imgur.com/KCa1JYo.png

It happens for titles like: 2, 02, 000002. Basically always if (int)$page_title == $front_page_id

The wrong is_front_page flag may affect themes/plugins which use it.

It's quite rare for the bug to take effect, but it happens, as I got a report from a user of my theme.

[tyxla]

I was able to reproduce the described issue. That's such an interesting bug.

This is caused by the (expected) ambiguous behavior of the is_page() conditional tag, which is used within is_front_page().

As the documentation states, is_page() accepts: Page ID, title, slug, path, or array of such, so in that case 2 is being accepted as title, which is why the is_front_page() function returns true.

Patch with a fix is coming in a minute.

[tyxla]

Fixing is_front_page() conflicts with the titles of other page when they are the same like the ID of the front page. Including a unit test for that case.

[DrewAPicture]

#31009 was marked as a duplicate.

[MikeHansenMe]

Tested this and it worked as expected. Unit test also passes.