From: Andreas Gruenbacher <agruen@suse.de>
Subject: Add a -C option to specify an alternative config file

Add this patch without applying it for now; we need additional
changes before the config file can be created in the build
system without being root.

Index: graphviz-2.6/lib/common/args.c
===================================================================
--- graphviz-2.6.orig/lib/common/args.c
+++ graphviz-2.6/lib/common/args.c
@@ -122,6 +122,16 @@ config_extra_args(GVC_t *gvc, int argc, 
     if (arg && *arg == '-') {
       switch (arg[1]) {
       case 'c' : Config = TRUE; break;
+      case 'C' : 
+	if (!arg[2]) {
+          fprintf (stderr, "No argument for -C flag\n");
+          dotneato_usage (1);
+	}
+	if (gvc->config_path)
+	  free(gvc->config_path);
+	gvc->config_path = gmalloc(strlen(arg+1) + 1);
+        strcpy(gvc->config_path, arg+1);
+	break;
       default :
         cnt++;
         if (*p != arg) *p = arg;
Index: graphviz-2.6/lib/common/input.c
===================================================================
--- graphviz-2.6.orig/lib/common/input.c
+++ graphviz-2.6/lib/common/input.c
@@ -64,7 +64,8 @@ static char *memtestItems = "\n\
 static char *configFlags = "(additional options for config)  [-c]\n";
 static char *configItems = "\n\
  -c          - Configure plugins (Writes $prefix/lib/graphviz/config \n\
-               with available plugin information.  Needs write priviledge.)\n";
+               with available plugin information.  Needs write priviledge.)\n\
+ -C file     - Use an alternative config file.\n";
 
 void dotneato_usage(int exval)
 {