Allow fine-grained image-cache flushing.

* dispextern.h (struct image): Add `dependencies' field.
(clear_image_caches): Change arg to Lisp_Object.
* image.c (make_image): Initialize `dependencies' field.
(clear_image_cache): Change arg to allow fine-grained flushing.
Perform the flush even if image-cache-eviction-delay is nil.
(clear_image_caches): Change arg to Lisp_Object.
(Fclear_image_cache): Expand meaning of the argument.
(mark_image): Mark `dependencies' field.
* xfaces.c (clear_face_cache): Adapt arg to call to clear_image_caches.
(lface_hash): Use XHASH rather than XFASTINT.
(face_at_buffer_position): Fix int -> EMACS_INT position.
* xdisp.c (next_overlay_change): Fix int -> EMACS_INT position.
(select_frame_for_redisplay): Remove code duplication.
(redisplay_internal): Adapt arg to call to clear_image_caches.

1 files changed, 6 insertions, 4 deletions

diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index ee3c828857a..c647111047c 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -4364,10 +4364,12 @@ This works by removing all image with image specifications matching
 displayed, Emacs will load the image again.
 @end defun
 
-@defun clear-image-cache &optional frame
-This function clears the entire image cache.  If @var{frame} is
-non-@code{nil}, only the cache for that frame is cleared.  Otherwise,
-all frames' caches are cleared.
+@defun clear-image-cache &optional filter
+This function clears the image cache.  If @var{filter} is
+a frame, only the cache for that frame is cleared.  If omitted or
+@code{nil}, clear the images on the selected frame.  If @code{t},
+all frames' caches are cleared.  Otherwise, @var{filter} is taken as
+a file name and only images that reference this file will be flushed.
 @end defun
 
 If an image in the image cache has not been displayed for a specified