Slug generation breaks when the first part of entry name is uppercase

[RoseDMH]

Description

SIMILAR to #4266, possibly related.

When the entry title is in the format UPPERCASElowercase (for example "VAPORwave") a hyphen is added to the slug before the last uppercase letter, even if there are no spaces at all in the original string (so the previous example would become "vapo-rwave" in the slug).

Steps to reproduce

1. Create an entry with a title that has an uppercase portion and a lowercase portion, in that order, with no spaces.
   2.Save the entry and check the automatically generated slug. A hyphen should appear between the final and the penultimate letter of the uppercase portion.

Additional info

• Craft version:Craft Pro 3.1.28
• PHP version:7.3.1
• Database driver & version:MySQL 5.5.5

[brandonkelly]

That is expected behavior. Craft is interpreting this as an uppercase word (VAPO) followed by a camel-cased word (Rwave), which is generally a safe assumption with strings like this. (For example, see the oldHTMLFile example in the Camel Case Wikipedia entry.)

[terryupton]

Also perhaps related to the above and #4266 - I am seeing the following:
My title field is setup as follows {hotTubName}{stockCode} and then when I enter the following into the Stock Code field: 18T1018 it is creating the slug as follows:
sundance18-t1018 - I wouldn't expect this behaviour, I would expect the slug to be sundance18t1018

For now I have changed my title field to {hotTubName}-{stockCode|lower}

Thanks.