shr-color.el (shr-color-visible): Don't bug out if the colour names don't exist.

2 files changed, 35 insertions, 23 deletions

diff --git a/lisp/gnus/ChangeLog b/lisp/gnus/ChangeLog
index 2d821b29b64..a3305eb6c53 100644
--- a/lisp/gnus/ChangeLog
+++ b/lisp/gnus/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-25  Lars Magne Ingebrigtsen  <larsi@gnus.org>
+
+        * shr-color.el (shr-color-visible): Don't bug out if the colour names
+        don't exist.
+
 2010-11-25  Katsumi Yamaoka  <yamaoka@jpl.org>
 
         * mml.el (mml-preview): Make sure to bind gnus-displaying-mime to nil,
diff --git a/lisp/gnus/shr-color.el b/lisp/gnus/shr-color.el
index 2a4a6b3d4b7..c5ee8c721c8 100644
--- a/lisp/gnus/shr-color.el
+++ b/lisp/gnus/shr-color.el
@@ -324,29 +324,36 @@ If FIXED-BACKGROUND is set, and if the color are not visible, a
 new background color will not be computed. Only the foreground
 color will be adapted to be visible on BG."
   ;; Convert fg and bg to CIE Lab
-  (let* ((fg-lab (apply 'rgb->lab (rgb->normalize fg)))
-         (bg-lab (apply 'rgb->lab (rgb->normalize bg)))
-         ;; Compute color distance using CIE DE 2000
-         (fg-bg-distance (color-lab-ciede2000 fg-lab bg-lab))
-         ;; Compute luminance distance (substract L component)
-         (luminance-distance (abs (- (car fg-lab) (car bg-lab)))))
-    (if (and (>= fg-bg-distance shr-color-visible-distance-min)
-             (>= luminance-distance shr-color-visible-luminance-min))
-        (list bg fg)
-      ;; Not visible, try to change luminance to make them visible
-      (let ((Ls (set-minimum-interval (car bg-lab) (car fg-lab) 0 100
-                                      shr-color-visible-luminance-min
-                                      fixed-background)))
-        (unless fixed-background
-          (setcar bg-lab (car Ls)))
-        (setcar fg-lab (cadr Ls))
-        (list
-         (if fixed-background
-             bg
-           (apply 'format "#%02x%02x%02x"
-                  (mapcar (lambda (x) (* (max (min 1 x) 0) 255)) (apply 'lab->rgb bg-lab))))
-         (apply 'format "#%02x%02x%02x"
-                (mapcar (lambda (x) (* (max (min 1 x) 0) 255)) (apply 'lab->rgb fg-lab))))))))
+  (let ((fg-norm (rgb->normalize fg))
+        (bg-norm (rgb->normalize bg)))
+    (if (or (null fg-norm)
+            (null bg-norm))
+        (list bg fg)
+      (let* ((fg-lab (apply 'rgb->lab fg-norm))
+             (bg-lab (apply 'rgb->lab bg-norm))
+             ;; Compute color distance using CIE DE 2000
+             (fg-bg-distance (color-lab-ciede2000 fg-lab bg-lab))
+             ;; Compute luminance distance (substract L component)
+             (luminance-distance (abs (- (car fg-lab) (car bg-lab)))))
+        (if (and (>= fg-bg-distance shr-color-visible-distance-min)
+                 (>= luminance-distance shr-color-visible-luminance-min))
+            (list bg fg)
+          ;; Not visible, try to change luminance to make them visible
+          (let ((Ls (set-minimum-interval (car bg-lab) (car fg-lab) 0 100
+                                          shr-color-visible-luminance-min
+                                          fixed-background)))
+            (unless fixed-background
+              (setcar bg-lab (car Ls)))
+            (setcar fg-lab (cadr Ls))
+            (list
+             (if fixed-background
+                 bg
+               (apply 'format "#%02x%02x%02x"
+                      (mapcar (lambda (x) (* (max (min 1 x) 0) 255))
+                              (apply 'lab->rgb bg-lab))))
+             (apply 'format "#%02x%02x%02x"
+                    (mapcar (lambda (x) (* (max (min 1 x) 0) 255))
+                            (apply 'lab->rgb fg-lab))))))))))
 
 (provide 'shr-color)