What logic travis used to recognize "gh-pages" branch?

Hi,

I am currently working on github pages and I have a question.

github pages branch by documentation1 defined that the branch named “gh-pages” can be a branch holding the github pages. On travis point of view. this branch shouldn’t be build and this is understandable.

However, for the branch containing gh-pages/gh_pages. Currently travis seems regarding them all as a gh-pages branch. below are the examples:

fix/fix-gh-pages-build
fix/fix-gh-pages-building
fix/fix-gh_pages-build

These branches having the name “gh-pages” in the middle and returnd " GitHub Pages branch not included via configuration. " in travis build request.

I am not going to build2 the gh-pages using travis. I am just fixing some code to build the gh-pages.
So the terms “gh-pages” may appears on the branch name.

Thanks in advance.

BR,
Louis