fix: roundup-demo, interactive mode would nuke an existing tracker.

Tonu Mikk demonstrated a bug in roundup-demo. When invoked without a
tracker home on the command line, it would nuke an existing directory
specified interactively.

There is still a minor bug. If an invalid home directory is specified,
roundup-demo will prompt for the template to use before reporting:

  Error: Refusing to nuke non-tracker directory:

but this doesn't cause data loss so not worth fixing at this time.

Author: rouilj

CHANGES.txt

@@ -81,6 +81,8 @@ Fixed:
   is used to install the share tree. The lets Roundup find tracker
   templates and translation files. (Found by Simon Eigeldinger, fix
   John Rouillard)
+- fix roundup-demo, interactive mode would nuke an existing tracker.
+  (Found Tonu Mikk, fix John Rouillard)
 
 Features:
 

roundup/scripts/roundup_demo.py

@@ -138,6 +138,12 @@ def run():
     template = cli_args.template or DEFAULT_TEMPLATE
     backend = cli_args.backend_db or cli_backend or DEFAULT_BACKEND
 
+    if not tracker_home:
+        home = my_input(
+            _('Enter directory path to create demo tracker [%s]: ') % home)
+        if not home:
+            home = DEFAULT_HOME
+
     # if there is no tracker in home, force nuke
     try:
         instance.open(home)
@@ -151,12 +157,6 @@ def run():
         # FIXME: i'd like to have an option to abort the tracker creation
         #   say, by entering a single dot.  but i cannot think of
         #   appropriate prompt for that.
-        if not tracker_home:
-            home = my_input(
-                _('Enter directory path to create demo tracker [%s]: ') % home)
-            if not home:
-                home = DEFAULT_HOME
-
         if not cli_args.template in templates:
             template = my_input(
             _('Enter tracker template to use (one of (%(template_list)s)) [%(default_template)s]: ') %