Fix bug #16378 with mishandling of empty faces.

 lisp/faces.el (face-spec-choose): Accept additional optional argument,
 whose value is returned if no matching attributes are found.
 (face-spec-recalc): Use the new optional argument when calling
 face-spec-choose.

2 files changed, 25 insertions, 9 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a74e121c6bd..bb283ab84df 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -3,6 +3,10 @@
         * faces.el (face-spec-recalc): Call make-face-x-resource-internal
         only when inhibit-x-resources is nil, and do that earlier in the
         function.  Doc fix.  (Bug#16694)
+        (face-spec-choose): Accept additional optional argument, whose
+        value is returned if no matching attributes are found.
+        (face-spec-recalc): Use the new optional argument when calling
+        face-spec-choose.  (Bug#16378)
 
 2014-04-04  Tassilo Horn  <tsdh@gnu.org>
 
diff --git a/lisp/faces.el b/lisp/faces.el
index c6dd8d7a2d5..1255d7c9ff7 100644
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -1512,13 +1512,15 @@ If FRAME is nil, the current FRAME is used."
     match))
 
 
-(defun face-spec-choose (spec &optional frame)
-  "Choose the proper attributes for FRAME, out of SPEC.
-If SPEC is nil, return nil."
+(defun face-spec-choose (spec &optional frame no-match-retval)
+  "Return the proper attributes for FRAME, out of SPEC.
+
+If no match is found or SPEC is nil, return nil, unless NO-MATCH-RETVAL
+is given, in which case return its value instead."
   (unless frame
     (setq frame (selected-frame)))
   (let ((tail spec)
-        result defaults)
+        result defaults match-found)
     (while tail
       (let* ((entry (pop tail))
              (display (car entry))
@@ -1538,9 +1540,18 @@ If SPEC is nil, return nil."
             (setq defaults thisval)
           ;; Otherwise, if it matches, use it.
           (when (face-spec-set-match-display display frame)
-            (setq result thisval)
-            (setq tail nil)))))
-    (if defaults (append result defaults) result)))
+            (setq result thisval
+                  tail nil
+                  match-found t)))))
+    ;; If defaults have been found, it's safe to just append those to the result
+    ;; list (which at this point will be either nil or contain actual specs) and
+    ;; return it to the caller. Since there will most definitely be something to
+    ;; return in this case, there's no need to know/check if a match was found.
+    (if defaults
+        (append result defaults)
+      (if match-found
+          result
+        no-match-retval))))
 
 
 (defun face-spec-reset-face (face &optional frame)
@@ -1635,11 +1646,12 @@ After the reset, the specs are applied from the following sources in this order:
   ;; If FACE is customized or themed, set the custom spec from
   ;; `theme-face' records.
   (let ((theme-faces (get face 'theme-face))
+        (no-match-found 0)
         spec theme-face-applied)
     (if theme-faces
         (dolist (elt (reverse theme-faces))
-          (setq spec (face-spec-choose (cadr elt) frame))
-          (when spec
+          (setq spec (face-spec-choose (cadr elt) frame no-match-found))
+          (unless (eq spec no-match-found)
             (face-spec-set-2 face frame spec)
             (setq theme-face-applied t))))
     ;; If there was a spec applicable to FRAME, that overrides the