Merge lp:~manishsinha/software-properties/fix-887249-handle-404-error into lp:software-properties

[Manish Sinha (मनीष सिन्हा)]

In case the user provides a wrong username or ppa name, then the exception is handled

* The exception handler checks that if the username starts with a ~, in this case
  it suggests does the user mean the username without a ~. e.g. if the user does
  sudo apt-add-repository ppa:~gnome3team/stable, then the script will ask the user
  if he means ppa:gnome3team/stable
* Even better friendlier messages can be provided, but for that it will introduce
  lauchpadlib as a dependency

In case the user provides a wrong username or ppa name, then the exception is handled

* The exception handler checks that if the username starts with a ~, in this case
  it suggests does the user mean the username without a ~. e.g. if the user does
  sudo apt-add-repository ppa:~gnome3team/stable, then the script will ask the user
  if he means ppa:gnome3team/stable
* Even better friendlier messages can be provided, but for that it will introduce
  lauchpadlib as a dependency

=== modified file 'add-apt-repository'
--- add-apt-repository	2011-10-18 19:16:25 +0000
+++ add-apt-repository	2011-11-07 19:23:24 +0000
@@ -10,6 +10,7 @@
 from aptsources.sourceslist import SourceEntry
 from optparse import OptionParser
 from gettext import gettext as _
+from urllib2 import HTTPError
 
 def utf8(s):
     """
@@ -85,7 +86,13 @@
         from softwareproperties.ppa import get_ppa_info_from_lp
         user, sep, ppa_name = line.split(":")[1].partition("/")
         ppa_name = ppa_name or "ppa"
-        ppa_info = get_ppa_info_from_lp(user, ppa_name)
+        try:
+            ppa_info = get_ppa_info_from_lp(user, ppa_name)
+        except HTTPError:
+            print _("Cannot add PPA. Please check that the PPA name or format is correct")
+            if user.startswith("~"):
+                print _("Did you mean ppa:%s/%s" %(user[1:], ppa_name))
+            sys.exit(1)
         if options.remove:
             print _("You are about to remove the following PPA from your system:")
         else: