self_update implies push_isabelle_home (see also 4c253e84ae62);

--- a/src/Pure/Admin/build_history.scala	Sat Mar 03 13:23:09 2018 +0100
+++ b/src/Pure/Admin/build_history.scala	Sat Mar 03 14:27:33 2018 +0100
@@ -508,7 +508,6 @@
     afp_repos_source: String = AFP.repos_source,
     isabelle_identifier: String = "remote_build_history",
     self_update: Boolean = false,
-    push_isabelle_home: Boolean = false,
     progress: Progress = No_Progress,
     rev: String = "",
     afp_rev: Option[String] = None,
@@ -517,7 +516,7 @@
   {
     /* Isabelle self repository */
 
-    val isabelle_hg =
+    val self_hg =
       Mercurial.setup_repository(isabelle_repos_source, isabelle_repos_self, ssh = ssh)
 
     def execute(cmd: String, args: String, echo: Boolean = false, strict: Boolean = true): Unit =
@@ -529,18 +528,11 @@
         strict = strict).check
 
     if (self_update) {
-      val self_rev =
-        if (push_isabelle_home) {
-          val isabelle_home_hg = Mercurial.repository(Path.explode("~~"))
-          val self_rev = isabelle_home_hg.id()
-          isabelle_home_hg.push(isabelle_hg.root_url, rev = self_rev, force = true)
-          self_rev
-        }
-        else {
-          isabelle_hg.pull()
-          isabelle_hg.id()
-        }
-      isabelle_hg.update(rev = self_rev, clean = true)
+      val hg = Mercurial.repository(Path.explode("~~"))
+      val self_rev = hg.id()
+      hg.push(self_hg.root_url, rev = self_rev, force = true)
+      self_hg.update(rev = self_rev, clean = true)
+
       execute("bin/isabelle", "components -I")
       execute("bin/isabelle", "components -a", echo = true)
       execute("Admin/build", "jars_fresh")

--- a/src/Pure/Admin/isabelle_cronjob.scala	Sat Mar 03 13:23:09 2018 +0100
+++ b/src/Pure/Admin/isabelle_cronjob.scala	Sat Mar 03 14:27:33 2018 +0100
@@ -306,16 +306,12 @@
       {
         using(r.ssh_session(logger.ssh_context))(ssh =>
           {
-            val self_update = !r.shared_home
-            val push_isabelle_home = self_update && Mercurial.is_repository(Path.explode("~~"))
-
             val results =
               Build_History.remote_build_history(ssh,
                 isabelle_repos,
                 isabelle_repos.ext(r.host),
                 isabelle_identifier = "cronjob_build_history",
-                self_update = self_update,
-                push_isabelle_home = push_isabelle_home,
+                self_update = !r.shared_home,
                 rev = rev,
                 afp_rev = afp_rev,
                 options =