Add a PhaseStop() function, which gracefully stops the update process,

so that we can tell the user to do something. For example, after
installing xerces, we need the user to reconfig/rebuild the object
tree and restart the installation.

install/libinstall.pm.in

@@ -13,12 +13,14 @@ use Exporter;
 use vars qw(@EXPORT $TOP_OBJDIR $TOP_SRCDIR
 	    $TBROOT $LOGDIR $MAINSITE $PGENISUPPORT $GMAKE $PKG_INFO
 	    $PORTSDIR $VARRUN $RCDIR $MYSQL $DBNAME
-	    $SQL_UPDATE_MAJOR_REVISION $INSTALL_UPDATE_MAJOR_REVISION);
+	    $SQL_UPDATE_MAJOR_REVISION $INSTALL_UPDATE_MAJOR_REVISION
+	    $HAVE_XERCES);
 
 @EXPORT = qw($TOP_OBJDIR $TOP_SRCDIR
 	     $TBROOT $LOGDIR $MAINSITE $PGENISUPPORT $GMAKE $PKG_INFO
 	     $PORTSDIR $VARRUN $RCDIR $MYSQL $DBNAME
-	     $SQL_UPDATE_MAJOR_REVISION $INSTALL_UPDATE_MAJOR_REVISION);
+	     $SQL_UPDATE_MAJOR_REVISION $INSTALL_UPDATE_MAJOR_REVISION
+	     $HAVE_XERCES);
 
 # Configure variables
 
@@ -35,6 +37,7 @@ $RCDIR         = "/usr/local/etc/rc.d";
 
 $DBNAME        = "@TBDBNAME@";
 $MYSQL         = "/usr/local/bin/mysql";
+$HAVE_XERCES   = "@HAVE_XERCES@";
 
 # Change these if the major numbers in sql/updates or install/updates
 # are changed.
@@ -148,6 +151,7 @@ sub Phase($$$) {
     #
     my $message = "";
     my $die = 0;
+    my $stop = 0;
     if ($hasSubPhase) {
 	print  "| " x ($depth -1) . "+-" . "--" x (24 - $depth) . "> ";
     }
@@ -180,6 +184,28 @@ sub Phase($$$) {
 	    last SWITCH;
 	};
 
+	(/^stop$/) && do {
+	    print "[ Stopped    ]\n";
+	    print $logfp "[ Stopped ($libinstall::reason) ]\n"
+		if ($impotent && defined($logfp));
+	    $$parentNonSkipped++;
+	    $message = "$libinstall::reason";
+	    if ($impotent) {
+		$libinstall::phaseResults{$name} = "succeed";
+	    }
+	    else {
+		$libinstall::phaseResults{$name} = $_;
+		$stop = 1;
+		if ($isSubPhase) {
+		    #
+		    # Propagate failure up the tree
+		    #
+		    PhaseStop($libinstall::reason);
+		}
+	    }
+	    last SWITCH;
+	};
+
 	(undef || /^$/ || /^succeed$/) && do {
 	    #
 	    # If we're a parent, and all sub-phases got skipped, we did too
@@ -229,6 +255,18 @@ sub Phase($$$) {
 	}
     }
 
+    #
+    # If we decided that we need to stop, do that now
+    #
+    if ($stop) {
+	print "\n";
+	print "############################################################\n";
+	print "Installation stopped in phase $name. The reason is:\n";
+	print "$message\n";
+	print "############################################################\n";
+	exit -1;
+    }
+
     #
     # If we decided that we need to die, do that now
     #
@@ -268,6 +306,14 @@ sub PhaseFail($) {
     throw "fail";
 }
 
+#
+# Signal that the current phase needs to stop so the user can do something.
+#
+sub PhaseStop($) {
+    ($libinstall::reason) = (@_);
+    throw "stop";
+}
+
 #
 # Signal that the current phase is being skipped
 #