correct 'import' in ac2e0a26ac

gramps/gen/plug/docgen/graphdoc.py

@@ -8,8 +8,9 @@
 # Copyright (C) 2007       Brian G. Matherly
 # Copyright (C) 2009       Benny Malengier
 # Copyright (C) 2009       Gary Burton
-# Copyright (C) 2017       Mindaugas Baranauskas
+# Copyright (C) 2013       Mindaugas Baranauskas <embar@super.lt>
 # Copyright (C) 2017       Paul Culley
+# Copyright (C) 2017       Paul Franklin
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -911,6 +912,15 @@ class GVPdfGsDoc(GVDocBase):
         options.menu.get_option_by_name('dpi').set_value(72)
         GVDocBase.__init__(self, options, paper_style)
 
+    def init(self):
+        """
+        tell the user how to enable this output format, if necessary
+        """
+        if _GS_CMD == '':
+            from ...errors import ReportError
+            raise ReportError(_("'Ghostscript' is not installed"),
+                              _("Use your package manager to install it"))
+
     def close(self):
         """ Implements GVPdfGsDoc.close() """
         GVDocBase.close(self)
@@ -1007,12 +1017,11 @@ FORMATS = []
 
 if _DOT_FOUND:
 
-    if _GS_CMD != "":
-        FORMATS += [{'type' : "gspdf",
-                     'ext'  : "pdf",
-                     'descr': _("PDF (Ghostscript)"),
-                     'mime' : "application/pdf",
-                     'class': GVPdfGsDoc}]
+    FORMATS += [{'type' : "gspdf",
+                 'ext'  : "pdf",
+                 'descr': _("PDF (Ghostscript)"),
+                 'mime' : "application/pdf",
+                 'class': GVPdfGsDoc}]
 
     FORMATS += [{'type' : "gvpdf",
                  'ext'  : "pdf",