Introduce new VIR_DOMAIN_EVENT_DEFINED_FROM_SNAPSHOT sub-event

VIR_DOMAIN_EVENT_DEFINED_FROM_SNAPSHOT event should be emitted
when domain configuration was changed on revert to snapshot.

examples/object-events/event-test.c

@@ -110,6 +110,8 @@ static const char *eventDetailToString(int event, int detail) {
                 ret = "Updated";
             else if (detail == VIR_DOMAIN_EVENT_DEFINED_RENAMED)
                 ret = "Renamed";
+            else if (detail == VIR_DOMAIN_EVENT_DEFINED_FROM_SNAPSHOT)
+                ret = "Snapshot";
             break;
         case VIR_DOMAIN_EVENT_UNDEFINED:
             if (detail == VIR_DOMAIN_EVENT_UNDEFINED_REMOVED)

include/libvirt/libvirt-domain.h

@@ -2346,6 +2346,7 @@ typedef enum {
     VIR_DOMAIN_EVENT_DEFINED_ADDED = 0,     /* Newly created config file */
     VIR_DOMAIN_EVENT_DEFINED_UPDATED = 1,   /* Changed config file */
     VIR_DOMAIN_EVENT_DEFINED_RENAMED = 2,   /* Domain was renamed */
+    VIR_DOMAIN_EVENT_DEFINED_FROM_SNAPSHOT = 3,   /* Config was restored from a snapshot */
 
 # ifdef VIR_ENUM_SENTINELS
     VIR_DOMAIN_EVENT_DEFINED_LAST

tools/virsh-domain.c

@@ -11410,7 +11410,8 @@ VIR_ENUM_IMPL(virshDomainEventDefined,
               VIR_DOMAIN_EVENT_DEFINED_LAST,
               N_("Added"),
               N_("Updated"),
-              N_("Renamed"))
+              N_("Renamed"),
+              N_("Snapshot"))
 
 VIR_ENUM_DECL(virshDomainEventUndefined)
 VIR_ENUM_IMPL(virshDomainEventUndefined,