Add a `M-c' command to `read-regexp'

* doc/lispref/minibuf.texi (Text from Minibuffer): Document it.

* lisp/replace.el (read-regexp): Add a `M-c' command to indicate
case folding (bug#16913).

1 files changed, 14 insertions, 0 deletions

diff --git a/doc/lispref/minibuf.texi b/doc/lispref/minibuf.texi
index 1451e59d05c..a59261cb9df 100644
--- a/doc/lispref/minibuf.texi
+++ b/doc/lispref/minibuf.texi
@@ -309,6 +309,20 @@ The optional argument @var{history}, if non-@code{nil}, is a symbol
 specifying a minibuffer history list to use (@pxref{Minibuffer
 History}).  If it is omitted or @code{nil}, the history list defaults
 to @code{regexp-history}.
+
+The user can use the @kbd{M-c} command to indicate whether case
+folding should be on or off.  If the user has used this command, the
+returned string will have the text property @code{case-fold} set to
+either @code{fold} or @code{inhibit-fold}.  It is up to the caller of
+@code{read-regexp} to actually use this value, and the convenience
+function @code{read-regexp-case-fold-search} is provided for that.  A
+typical usage pattern here might look like:
+
+@lisp
+(let* ((regexp (read-regexp "Search for: "))
+       (case-fold-search (read-regexp-case-fold-search regexp)))
+  (re-search-forward regexp))
+@end lisp
 @end defun
 
 @defopt read-regexp-defaults-function