From 5989ba2f87b231d9421ec13fb9e0811767921aa5 Mon Sep 17 00:00:00 2001
From: Chong Yidong <cyd@stupidchicken.com>
Date: Fri, 20 Jun 2008 23:27:07 +0000
Subject: [PATCH] (Ffont_face_attributes): Omit key-attribute pairs not defined
 by the font.

---
 src/font.c | 45 ++++++++++++++++++++++++++++++---------------
 1 file changed, 30 insertions(+), 15 deletions(-)

diff --git a/src/font.c b/src/font.c
index d49a19acac0..f10235249f6 100644
--- a/src/font.c
+++ b/src/font.c
@@ -3733,7 +3733,8 @@ The return value is a list of the form
 \(:family FAMILY :height HEIGHT :weight WEIGHT :slant SLANT :width WIDTH)
 
 where FAMILY, HEIGHT, WEIGHT, SLANT, and WIDTH are face attribute values
-compatible with `set-face-attribute'.
+compatible with `set-face-attribute'.  Some of these key-attribute pairs
+may be omitted from the list if they are not specified by FONT.
 
 The optional argument FRAME specifies the frame that the face attributes
 are to be displayed on.  If omitted, the selected frame is used.  */)
@@ -3743,6 +3744,7 @@ are to be displayed on.  If omitted, the selected frame is used.  */)
   struct frame *f;
   Lisp_Object plist[10];
   Lisp_Object val;
+  int n = 0;
 
   if (NILP (frame))
     frame = selected_frame;
@@ -3762,36 +3764,49 @@ are to be displayed on.  If omitted, the selected frame is used.  */)
   else if (! FONTP (font))
     signal_error ("Invalid font object", font);
 
-  plist[0] = QCfamily;
   val = AREF (font, FONT_FAMILY_INDEX);
-  plist[1] = NILP (val) ? Qnil : SYMBOL_NAME (val);
+  if (! NILP (val))
+    {
+      plist[n++] = QCfamily;
+      plist[n++] = SYMBOL_NAME (val);
+    }
 
-  plist[2] = QCheight;
   val = AREF (font, FONT_SIZE_INDEX);
   if (INTEGERP (val))
     {
       Lisp_Object font_dpi = AREF (font, FONT_DPI_INDEX);
       int dpi = INTEGERP (font_dpi) ? XINT (font_dpi) : f->resy;
-      plist[3] = make_number (10 * PIXEL_TO_POINT (XINT (val), dpi));
+      plist[n++] = QCheight;
+      plist[n++] = make_number (10 * PIXEL_TO_POINT (XINT (val), dpi));
     }
   else if (FLOATP (val))
-    plist[3] = make_number (10 * (int) XFLOAT_DATA (val));
-  else
-    plist[3] = Qnil;
+    {
+      plist[n++] = QCheight;
+      plist[n++] = make_number (10 * (int) XFLOAT_DATA (val));
+    }
 
-  plist[4] = QCweight;
   val = FONT_WEIGHT_FOR_FACE (font);
-  plist[5] = NILP (val) ? Qnormal : val;
+  if (! NILP (val))
+    {
+      plist[n++] = QCweight;
+      plist[n++] = val;
+    }
 
-  plist[6] = QCslant;
   val = FONT_SLANT_FOR_FACE (font);
-  plist[7] = NILP (val) ? Qnormal : val;
+  if (! NILP (val))
+    {
+      plist[n++] = QCslant;
+      plist[n++] = val;
+    }
 
-  plist[8] = QCwidth;
   val = FONT_WIDTH_FOR_FACE (font);
-  plist[9] = NILP (val) ? Qnormal : val;
+  if (! NILP (val))
+    {
+      plist[n++] = QCwidth;
+      plist[n++] = val;
+    }
 
-  return Flist (10, plist);
+  return Flist (n, plist);
 }
 
 #endif
-- 
2.39.2