* customize.texi (Custom Themes): Document custom-known-themes.

* custom.el (custom-available-themes): Doc fix.

Fixes: debbugs:15717

2 files changed, 9 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index efb12d34d54..e8bd967c0f2 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -11,6 +11,7 @@
         * custom.el (custom-push-theme): If custom--inhibit-theme-enable
         is non-nil, do not create a new entry in the symbol's theme-value
         or theme-face property; update theme-settings only (Bug#14664).
+        (custom-available-themes): Doc fix.
 
         * cus-theme.el (custom-new-theme-mode-map): Add bindings
         (Bug#15674).
diff --git a/lisp/custom.el b/lisp/custom.el
index 1d00dda0168..43775a16911 100644
--- a/lisp/custom.el
+++ b/lisp/custom.el
@@ -1277,7 +1277,14 @@ NAME should be a symbol."
                 (eq name 'changed)))))
 
 (defun custom-available-themes ()
-  "Return a list of available Custom themes (symbols)."
+  "Return a list of Custom themes available for loading.
+Search the directories specified by `custom-theme-load-path' for
+files named FOO-theme.el, and return a list of FOO symbols.
+
+The returned symbols may not correspond to themes that have been
+loaded, and no effort is made to check that the files contain
+valid Custom themes.  For a list of loaded themes, check the
+variable `custom-known-themes'."
   (let (sym themes)
     (dolist (dir (custom-theme--load-path))
       (when (file-directory-p dir)