+** Interactive searching and matching case improvements:
+Case sensitiveness in searching operations is controled by the variable
+`case-fold-search' (if non-nil, case is ignored while searching). This
+mechanism has now been slightly improved in the case of an interactive
+search: if the search string (or regexp) happens to contain uppercase
+characters, the searching is forced to be case-sensitive, regardless of
+the value of `case-fold-search'. This behavior affects all functions
+performing interactive searches, like `zap-to-char', `tags-search',
+`occur' etc.
+