src/Pure/System/isabelle_system.scala

--- a/src/Pure/System/isabelle_system.scala	Wed Sep 12 16:27:44 2012 +0200
+++ b/src/Pure/System/isabelle_system.scala	Wed Sep 12 16:54:24 2012 +0200
@@ -11,7 +11,7 @@
 import java.util.regex.Pattern
 import java.util.Locale
 import java.io.{InputStream, OutputStream, File => JFile, BufferedReader, InputStreamReader,
-  BufferedWriter, OutputStreamWriter, IOException}
+  BufferedWriter, OutputStreamWriter, IOException, FileInputStream, BufferedInputStream}
 import java.awt.{GraphicsEnvironment, Font}
 import java.awt.font.TextAttribute
 
@@ -297,7 +297,12 @@
   def install_fonts()
   {
     val ge = GraphicsEnvironment.getLocalGraphicsEnvironment()
-    for (font <- Path.split(getenv_strict("ISABELLE_FONTS")))
+    for (font <- Path.split(getenv_strict("ISABELLE_FONTS"))) {
       ge.registerFont(Font.createFont(Font.TRUETYPE_FONT, font.file))
+
+      val stream = new BufferedInputStream(new FileInputStream(font.file))
+      try { javafx.scene.text.Font.loadFont(stream, 1.0) }
+      finally { stream.close }
+    }
   }
 }