(save-match-data): Add comment about using evaporate arg

to set-match-data.

2 files changed, 9 insertions, 0 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index 15c23ebc81b..cb8006c10a7 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2020,6 +2020,8 @@ The value returned is the value of the last form in BODY."
         '((save-match-data-internal (match-data)))
         (list 'unwind-protect
               (cons 'progn body)
+              ;; It is safe to free (evaporate) markers immediately here,
+              ;; as Lisp programs should not copy from save-match-data-internal.
               '(set-match-data save-match-data-internal 'evaporate))))
 
 (defun match-string (num &optional string)
diff --git a/src/ChangeLog b/src/ChangeLog
index 659f1066efc..72890cbc545 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2005-06-23  Kim F. Storm  <storm@cua.dk>
+
+        * search.c (Fmatch_data): Remove evaporate option.
+        (Fmatch_data): Do not mention evaporate option in doc string.
+        Add commentary explaining evaporate arg (for internal use only).
+        (unwind_set_match_data): Add comment on evaporate use.
+
 2005-06-22  Miles Bader  <miles@gnu.org>
 
         * xfaces.c (Qvertical_border): Renamed from `Qvertical_divider'.