Add FC_DESKTOP_NAME property

To allow users to have desktop-specific matching rule.

fontconfig/fontconfig.h

@@ -128,6 +128,7 @@ typedef int		FcBool;
 #define FC_POSTSCRIPT_NAME  "postscriptname"	/* String */
 #define FC_FONT_HAS_HINT    "fonthashint"	/* Bool - true if font has hinting */
 #define FC_ORDER	    "order"		/* Integer */
+#define FC_DESKTOP_NAME     "desktop"		/* String */
 
 #define FC_CACHE_SUFFIX		    ".cache-" FC_CACHE_VERSION
 #define FC_DIR_CACHE_FILE	    "fonts.cache-" FC_CACHE_VERSION

src/fcdefault.c

@@ -211,28 +211,73 @@ retry:
     return prgname;
 }
 
+static FcChar8 *default_desktop_name;
+
+FcChar8 *
+FcGetDesktopName (void)
+{
+    FcChar8 *desktop_name;
+retry:
+    desktop_name = fc_atomic_ptr_get (&default_desktop_name);
+    if (!desktop_name)
+    {
+	char *s = getenv ("XDG_CURRENT_DESKTOP");
+
+	if (!s)
+	    desktop_name = FcStrdup ("");
+	else
+	    desktop_name = FcStrdup (s);
+	if (!desktop_name)
+	{
+	    fprintf (stderr, "Fontconfig error: out of memory in %s\n",
+		     __FUNCTION__);
+	    return NULL;
+	}
+
+	if (!fc_atomic_ptr_cmpexch(&default_desktop_name, NULL, desktop_name))
+	{
+	    free (desktop_name);
+	    goto retry;
+	}
+    }
+    if (desktop_name && !desktop_name[0])
+	return NULL;
+
+    return desktop_name;
+}
+
 void
 FcDefaultFini (void)
 {
     FcChar8  *lang;
     FcStrSet *langs;
     FcChar8  *prgname;
+    FcChar8  *desktop;
 
     lang = fc_atomic_ptr_get (&default_lang);
-    if (lang && fc_atomic_ptr_cmpexch (&default_lang, lang, NULL)) {
+    if (lang && fc_atomic_ptr_cmpexch (&default_lang, lang, NULL))
+    {
 	free (lang);
     }
 
     langs = fc_atomic_ptr_get (&default_langs);
-    if (langs && fc_atomic_ptr_cmpexch (&default_langs, langs, NULL)) {
+    if (langs && fc_atomic_ptr_cmpexch (&default_langs, langs, NULL))
+    {
 	FcRefInit (&langs->ref, 1);
 	FcStrSetDestroy (langs);
     }
 
     prgname = fc_atomic_ptr_get (&default_prgname);
-    if (prgname && fc_atomic_ptr_cmpexch (&default_prgname, prgname, NULL)) {
+    if (prgname && fc_atomic_ptr_cmpexch (&default_prgname, prgname, NULL))
+    {
 	free (prgname);
     }
+
+    desktop = fc_atomic_ptr_get (&default_desktop_name);
+    if (desktop && fc_atomic_ptr_cmpexch(&default_desktop_name, desktop, NULL))
+    {
+	free (desktop);
+    }
 }
 
 void
@@ -336,6 +381,13 @@ FcDefaultSubstitute (FcPattern *pattern)
 	    FcPatternObjectAddString (pattern, FC_PRGNAME_OBJECT, prgname);
     }
 
+    if (FcPatternObjectGet (pattern, FC_DESKTOP_NAME_OBJECT, 0, &v) == FcResultNoMatch)
+    {
+	FcChar8 *desktop = FcGetDesktopName ();
+	if (desktop)
+	    FcPatternObjectAddString (pattern, FC_DESKTOP_NAME_OBJECT, desktop);
+    }
+
     if (!FcPatternFindObjectIter (pattern, &iter, FC_ORDER_OBJECT))
 	FcPatternObjectAddInteger (pattern, FC_ORDER_OBJECT, 0);
 }

src/fcint.h

@@ -909,6 +909,9 @@ FcGetDefaultLang (void);
 FcPrivate FcChar8 *
 FcGetPrgname (void);
 
+FcPrivate FcChar8 *
+FcGetDesktopName (void);
+
 FcPrivate void
 FcDefaultFini (void);
 

src/fcobjs.h

@@ -74,4 +74,5 @@ FC_OBJECT (FONT_VARIATIONS,	FcTypeString,	NULL)
 FC_OBJECT (VARIABLE,		FcTypeBool,	FcCompareBool)
 FC_OBJECT (FONT_HAS_HINT,	FcTypeBool,	FcCompareBool)
 FC_OBJECT (ORDER,		FcTypeInteger,	FcCompareNumber)
+FC_OBJECT (DESKTOP_NAME,	FcTypeString,	NULL)
 /* ^-------------- Add new objects here. */