0a80449f4b81955b313a3ec01aa2b42c235c3948
braney
  Sun Aug 16 16:25:44 2015 -0700
implement the suggestion in note-18 of #6551.    Default track visibilities
are now stored in the cart.  The defaults are reloaded from trackDb on a
new cart, when the assembly is changed, or when "default tracks" is
pressed.

diff --git src/hg/inc/cart.h src/hg/inc/cart.h
index d1f5ee8..927d5aa 100644
--- src/hg/inc/cart.h
+++ src/hg/inc/cart.h
@@ -416,30 +416,31 @@
  * and optionally content-type part HTTP preamble to web page.  Don't
  * write any HTML though. */
 
 struct cart *cartForSession(char *cookieName, char **exclude,
 	struct hash *oldVars);
 /* This gets the cart without writing any HTTP lines at all to stdout. */
 
 void cartSetDbConnector(DbConnector connector);
 /* Set the connector that will be used by the cart to connect to the
  * database. Default connector is hConnectCart */
 
 void cartSetDbDisconnector(DbDisconnect disconnector);
 /* Set the connector that will be used by the cart to disconnect from the
  * database. Default disconnector is hDisconnectCart */
 
+#define CART_HAS_DEFAULT_VISIBILITY "defaultsSet"
 
 /* Libified constants and code that originally belonged only to hgSession
  * (now hgTracks uses them too): */
 #define hgSessionPrefix "hgS_"
 
 #define hgsOtherUserName hgSessionPrefix "otherUserName"
 #define hgsOtherUserSessionName hgSessionPrefix "otherUserSessionName"
 #define hgsDoOtherUser hgSessionPrefix "doOtherUser"
 
 #define hgsLoadUrlName hgSessionPrefix "loadUrlName"
 #define hgsDoLoadUrl hgSessionPrefix "doLoadUrl"
 
 #define namedSessionTable "namedSessionDb"
 
 void sessionTouchLastUse(struct sqlConnection *conn, char *encUserName,