Better handle errors when going to LP

debian/changelog

@@ -13,7 +13,10 @@ ubuntu-dev-tools (0.39ubuntu1) intrepid; urgency=low
   * common.py:
      - Add functions mkdir and readlist.
 
- -- Siegfried-Angel Gevatter Pujals <rainct@ubuntu.com>  Tue, 12 Aug 2008 20:09:42 +0200
+  [ Iain Lane ]
+  * pull-lp-source: Better handle errors when going to LP 
+
+ -- Iain Lane <iain@orangesquash.org.uk>  Wed, 13 Aug 2008 10:56:12 +0100
 
 ubuntu-dev-tools (0.38ubuntu1) intrepid; urgency=low
 

pull-lp-source

@@ -48,7 +48,7 @@ class BackportFromLP:
         links = re.findall('a href=\"(.*\.dsc)\"', contents)
         
         if len(links) == 1 and \
-	    subprocess.call(['dget', '-x', 'http://launchpad.net%s' % links[0]]) == 0:
+        subprocess.call(['dget', '-xu', 'http://launchpad.net%s' % links[0]]) == 0:
             print '\nSuccess!'
         else:
             raise ValueError, '\nFailed to fetch and extract the source. ' +\
@@ -84,15 +84,38 @@ if __name__ == '__main__':
         sys.exit(1)
 
     # Check package exists.
+    try:
+
         sourcePage = urllib2.urlopen("https://launchpad.net/ubuntu/%s/+source/%s" % \
             (release, package)).read()
         m = re.search('"/ubuntu/%s/\+source/%s/(\d[^"]+)"' % (release, \
             package.replace('+', '\+')), sourcePage)
+    
         if not m:
             print >> sys.stderr, "The '%s' package does not appear to exist in " \
                 "the '%s' release." % (package, release)
             sys.exit(1)
 
+    except urllib2.HTTPError, e: # Raised on 404
+           
+        if e.code == 404:
+
+            print >> sys.stderr, "The '%s' package does not appear to exist in " \
+                "the '%s' release." % (package, release)
+
+        else: # Other code, probably LP malfunction
+            
+            print >> sys.stderr, "Error when checking Launchpad for package: %s " % e
+
+        sys.exit(1)
+
+    except urllib2.URLError, e: # Other error (NXDOMAIN, ...)
+
+            (_, reason) = e.reason
+
+            print >> sys.stderr, "Error when checking Launchpad for package: %s " % reason
+            sys.exit(1)
+
     # All good - start downloading...
     try:
         print 'Attempting to get %s from release %s...' % \