[Bug-AUCTeX] bug#17195: TeX-texinfo-mode needs to set add-log-current-defun-function

[Glenn Morris]

Package: auctex
Version: 11.87.2

Using current Emacs trunk or emacs-24 branch:

emacs -Q
Install auctex via M-x list-packages and activate it.
Visit a texinfo file, make some changes, use `C-x 4 a' to add a
ChangeLog entry. It uses a poor value for the name of the "function"
that changed, when it should use the node. It works ok in Emacs 24.3.

Following the 2012-12-01 changes to add-log-current-defun in Emacs,
the AUCTeX texinfo mode needs to set add-log-current-defun-function
to 'texinfo-current-defun-name, if that function is defined.