Title + subtitle interaction swallows punctuation

[chbrown]

Ending a title with . seems to prevent the : from showing up when using a subtitle. E.g.:

At least et al.: The semantics of scalar modifiers

[fintelkai]

Biblatex interprets the abbreviation dot in "et al." as a sentence ending period. If the title ends in a sentence-ending punctuation, inserting the usual colon would be ugly. Suppose the title is a question "How do presuppositions work?" ... in that case we wouldn't want to insert a colon between the title and the subtitle. The solution is to signal to biblatex that the dot is not a sentence period. Two ways:

\title{At least et al.\isdot}

using the \isdot command of biblatex. This makes the bib-file non-portable, though, so a TeX-y solution may be better:

\title{At least et al.\@}

using the \@ device that TeX has to disambiguate periods. See http://latex-alive.tumblr.com/post/827168808/correct-punctuation-spaces.

More tangentially relevant discussion at http://tex.stackexchange.com/questions/170547/in-biblatex-treat-periods-in-journal-as-abbreviation-dots.

[I haven't tested either of these solutions, but I'm pretty sure either will work. Please comment if they don't and I'll reopen the issue.]

[chbrown]

I tested your suggestions; both .\isdot and .\@ solve the issue. Thanks for the clarification! — I added a short note about title/subtitle to info.semprag.org/style