Item12952: Improve behavior of bootstrap mode.

Make admin decisions based upon isBOOTSTRAP as early in execution as
possible, so that later changes to isBOOTSTRAP are not recognized.

By setting admin user early, it "sticks" when the initial foswiki
session is created.  This leaves the user logged in as admin after the
initial configuration is saved, so that they have a chance to make
changes to AdminGroup without getting locked out.

core/lib/Foswiki.pm

@@ -1768,6 +1768,11 @@ sub new {
     ASSERT( !$query || UNIVERSAL::isa( $query, 'Foswiki::Request' ) )
       if DEBUG;
 
+   # Override user to be admin if no configuration exists.
+   # Do this really early, so that later changes in isBOOTSTRAPPING can't change
+   # Foswiki's behavior.
+    $defaultUser = 'admin' if ( $Foswiki::cfg{isBOOTSTRAPPING} );
+
     unless ( defined $Foswiki::cfg{TempfileDir} && $Foswiki::cfg{TempfileDir} )
     {
 
@@ -2107,8 +2112,11 @@ sub new {
 
     #Monitor::MARK("Preferences all set up");
 
+    # Set both isadmin and authenticated contexts.   If the current user
+    # is admin, then they either authenticated, or we are in bootstrap.
     if ( $this->{users}->isAdmin( $this->{user} ) ) {
-        $this->{context}{isadmin} = 1;
+        $this->{context}{authenticated} = 1;
+        $this->{context}{isadmin}       = 1;
     }
 
     # Finish plugin initialization - register handlers

core/lib/Foswiki/Users.pm

@@ -610,9 +610,6 @@ True if the user is an admin
 sub isAdmin {
     my ( $this, $cUID ) = @_;
 
-    # If bootstrapping the configuration, always admin
-    return 1 if $Foswiki::cfg{isBOOTSTRAPPING};
-
     return 0 unless defined $cUID;
 
     return $this->{isAdmin}->{$cUID}