* custom.el (defcustom, custom-handle-keyword): Add :package-version

keyword.
(custom-add-package-version): New function. Sets value of new property
'custom-package-version from :package-version keyword.

* cus-edit.el (customize-package-emacs-version-alist): New variable.
(customize-changed-options): Add check for custom-package-version.
(customize-package-emacs-version): New function to look up Emacs
version corresponding to the given package version.

3 files changed, 67 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 59d12a7f41b..8a205081fa5 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,16 @@
 2006-04-10  Bill Wohler  <wohler@newt.com>
 
+        * custom.el (defcustom, custom-handle-keyword): Add
+        :package-version keyword.
+        (custom-add-package-version): New function. Sets value of new
+        property 'custom-package-version from :package-version keyword.
+
+        * cus-edit.el (customize-package-emacs-version-alist): New
+        variable.
+        (customize-changed-options): Add check for custom-package-version.
+        (customize-package-emacs-version): New function to look up Emacs
+        version corresponding to the given package version.
+
         * emacs-lisp/find-func.el (find-function-regexp): Allow dashes in
         defun name, in similar fashion to find-variable-regexp.
 
diff --git a/lisp/cus-edit.el b/lisp/cus-edit.el
index e2275ce356d..4de2a431392 100644
--- a/lisp/cus-edit.el
+++ b/lisp/cus-edit.el
@@ -786,7 +786,7 @@ when the action is chosen.")
     (if (or (and (= 1 (length children))
                  (memq (widget-type (car children))
                        '(custom-variable custom-face)))
-            (y-or-n-p "Reset all settings' buffer text to show current values?  "))
+            (y-or-n-p "Reset all settings' buffer text to show current values? "))
         (mapc (lambda (widget)
                 (if (memq (widget-get widget :custom-state)
                           '(modified changed))
@@ -1079,6 +1079,18 @@ Show the buffer in another window, but don't select it."
 (defvar customize-changed-options-previous-release "21.1"
   "Version for `customize-changed-options' to refer back to by default.")
 
+;; Packages will update this variable, so make it available.
+;;;###autoload
+(defvar customize-package-emacs-version-alist nil
+  "Alist that maps packages to alists of package to Emacs versions.
+The value alists map all package versions used with
+the :package-version keyword to Emacs versions.  Packages are
+symbols and versions are strings.
+
+For example:
+  '((MH-E (\"7.4\" \"22.1\") (\"8.0\" \"22.1\"))
+    (Gnus (\"5.11\" \"22.1\")))")
+
 ;;;###autoload
 (defalias 'customize-changed 'customize-changed-options)
 
@@ -1119,7 +1131,12 @@ that were added or redefined since that version."
   (let (found)
     (mapatoms
      (lambda (symbol)
-       (let ((version (get symbol 'custom-version)))
+        (let* ((package-version (get symbol 'custom-package-version))
+               (version
+                (or (and package-version
+                         (customize-package-emacs-version symbol
+                                                          package-version))
+                    (get symbol 'custom-version))))
          (if version
              (when (customize-version-lessp since-version version)
                (if (or (get symbol 'custom-group)
@@ -1135,6 +1152,31 @@ that were added or redefined since that version."
       (error "No user option defaults have been changed since Emacs %s"
              since-version))))
 
+(defun customize-package-emacs-version (symbol package-version)
+  "Return Emacs version of SYMBOL.
+PACKAGE-VERSION has the form (PACKAGE VERSION).  The VERSION of
+PACKAGE is looked up in the associated list
+`customize-package-emacs-version-alist' to find the version of
+Emacs that is associated with it."
+  (let (package-versions emacs-version)
+    ;; Use message instead of error since we want user to be able to
+    ;; see the rest of the symbols even if a package author has
+    ;; botched things up.
+    (cond ((not (listp package-version))
+           (message "Invalid package-version value for %s" symbol))
+          ((setq package-versions (assq (car package-version)
+                                        customize-package-emacs-version-alist))
+           (setq emacs-version
+                 (cadr (assoc (cadr package-version) package-versions)))
+           (unless emacs-version
+             (message "Package version of %s not found in %s" symbol
+                      "customize-package-emacs-version-alist")))
+          (t
+           (message "Package %s neglected to update %s"
+                    (car package-version)
+                    "customize-package-emacs-version-alist")))
+    emacs-version))
+
 (defun customize-version-lessp (version1 version2)
   ;; Why are the versions strings, and given that they are, why aren't
   ;; they converted to numbers and compared as such here?  -- fx
diff --git a/lisp/custom.el b/lisp/custom.el
index c67f3b06272..42872ca761c 100644
--- a/lisp/custom.el
+++ b/lisp/custom.el
@@ -268,6 +268,12 @@ The following keywords are meaningful:
         VALUE should be a string specifying that the variable was
         first introduced, or its default value was changed, in Emacs
         version VERSION.
+:package-version
+        VALUE should be a list with the form (PACKAGE VERSION)
+        specifying that the variable was first introduced, or its
+        default value was changed, in PACKAGE version VERSION.  This
+        keyword takes priority over :version.  The PACKAGE and VERSION
+        must appear in the alist `customize-package-emacs-version-alist'.
 :tag LABEL
         Use LABEL, a string, instead of the item's name, to label the item
         in customization menus and buffers.
@@ -489,6 +495,8 @@ Fourth argument TYPE is the custom option type."
          (custom-add-to-group value symbol type))
         ((eq keyword :version)
          (custom-add-version symbol value))
+        ((eq keyword :package-version)
+         (custom-add-package-version symbol value))
         ((eq keyword :link)
          (custom-add-link symbol value))
         ((eq keyword :load)
@@ -540,6 +548,10 @@ For other custom types, this has no effect."
   "To the custom option SYMBOL add the version VERSION."
   (put symbol 'custom-version (purecopy version)))
 
+(defun custom-add-package-version (symbol version)
+  "To the custom option SYMBOL add the package version VERSION."
+  (put symbol 'custom-package-version (purecopy version)))
+
 (defun custom-add-load (symbol load)
   "To the custom option SYMBOL add the dependency LOAD.
 LOAD should be either a library file name, or a feature name."