Merge pull request #654 from alex-konovalov/help-viewer-fix

Fix for using firefox as a help viewer

Author: markuspf

lib/helpview.gi

@@ -218,7 +218,7 @@ else # UNIX but not Mac OS X
   HELP_VIEWER_INFO.firefox := rec(
   type := "url",
   show := function(url)
-    Exec(Concatenation("firefox -remote \"openURL(file:", url, ")\""));
+    Exec(Concatenation("firefox \"file://", url,"\" >/dev/null 2>1 &"));
   end
   );