log-view-message-re

log-view-message-re is a variable defined in `log-view.el'.
Its value is

"^\\(?:revision \\(?1:[.0-9]+\\)\\(?:	.*\\)?\\|r\\(?1:[0-9]+\\) | .* | .*\\|D \\(?1:[.0-9]+\\) .*\\|[^ \n].*[^0-9\n][0-9][0-9]:[0-9][0-9][^0-9\n].*[^ \n]  .*@.*\n\\(?:  \\* \\(?1:.*\\)\\)?\\)$"

Documentation:
Regexp matching the text identifying a revision.
The match group number 1 should match the revision number itself.