init: Retain traditional restart behavior for critical and oneshot services.

Adds an SVC_RESTART state that's used for an explicit "restart" of a
running service.  This retains the traditional restart behavior for
critical and oneshot services (previously altered by 7e36edd8), whereby
these services are "simply restarted" instead of counting as a crash (for a
critical serivce) or going into the disabled state (for a oneshot service).
diff --git a/init/init.c b/init/init.c
index e0f2cf7..26adcc6 100755
--- a/init/init.c
+++ b/init/init.c
@@ -169,7 +169,7 @@
          * state and immediately takes it out of the restarting
          * state if it was in there
          */
-    svc->flags &= (~(SVC_DISABLED|SVC_RESTARTING|SVC_RESET));
+    svc->flags &= (~(SVC_DISABLED|SVC_RESTARTING|SVC_RESET|SVC_RESTART));
     svc->time_started = 0;
 
         /* running processes require no additional work -- if
@@ -366,14 +366,14 @@
         notify_service_state(svc->name, "running");
 }
 
-/* The how field should be either SVC_DISABLED or SVC_RESET */
+/* The how field should be either SVC_DISABLED, SVC_RESET, or SVC_RESTART */
 static void service_stop_or_reset(struct service *svc, int how)
 {
     /* The service is still SVC_RUNNING until its process exits, but if it has
      * already exited it shoudn't attempt a restart yet. */
     svc->flags &= (~SVC_RESTARTING);
 
-    if ((how != SVC_DISABLED) && (how != SVC_RESET)) {
+    if ((how != SVC_DISABLED) && (how != SVC_RESET) && (how != SVC_RESTART)) {
         /* Hrm, an illegal flag.  Default to SVC_DISABLED */
         how = SVC_DISABLED;
     }
@@ -405,6 +405,17 @@
     service_stop_or_reset(svc, SVC_DISABLED);
 }
 
+void service_restart(struct service *svc)
+{
+    if (svc->flags & SVC_RUNNING) {
+        /* Stop, wait, then start the service. */
+        service_stop_or_reset(svc, SVC_RESTART);
+    } else if (!(svc->flags & SVC_RESTARTING)) {
+        /* Just start the service since it's not running. */
+        service_start(svc, NULL);
+    } /* else: Service is restarting anyways. */
+}
+
 void property_changed(const char *name, const char *value)
 {
     if (property_triggers_enabled)
@@ -471,6 +482,17 @@
     }
 }
 
+static void msg_restart(const char *name)
+{
+    struct service *svc = service_find_by_name(name);
+
+    if (svc) {
+        service_restart(svc);
+    } else {
+        ERROR("no such service '%s'\n", name);
+    }
+}
+
 void handle_control_message(const char *msg, const char *arg)
 {
     if (!strcmp(msg,"start")) {
@@ -478,8 +500,7 @@
     } else if (!strcmp(msg,"stop")) {
         msg_stop(arg);
     } else if (!strcmp(msg,"restart")) {
-        msg_stop(arg);
-        msg_start(arg);
+        msg_restart(arg);
     } else {
         ERROR("unknown control msg '%s'\n", msg);
     }