From 3267f34ff94bc2f7b95390f311f4c6c9604a2a08 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@tremily.us>
Date: Mon, 1 Sep 2014 15:48:21 -0700
Subject: [PATCH] feeds: Raise an exception when adding a feed with a duplicate
 name

Avoid:

  $ r2e add example http://example.com/feed1
  $ r2e add example http://example.com/feed2
  $ r2e list
  1: [*] example (http://example.com/feed2 -> lkmorlan)
  2: [*] example (http://example.com/feed2 -> lkmorlan)

Instead, the second addition now prints:

  duplicate feed name 'example'

to stderr and exits with status 1.

Reported-by: Liam K Morland <Liam@Morland.ca>
Signed-off-by: W. Trevor King <wking@tremily.us>
---
 CHANGELOG          |  1 +
 rss2email/error.py | 12 ++++++++++--
 rss2email/feeds.py |  9 ++++++++-
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 382e626..dbcc6dd 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,4 +1,5 @@
 v3.9 (unreleased)
+    * Catch and error out if a user adds a feed with a duplicate name.
     * Split sender into both sendmail's -F and -f.
     * Fix an error with SMTPConnectionError inhertence order ("does not take keyword arguments").
     * Add a new `smtp-ssl-protocol` setting, to select acceptable protocols for SMTP connections.
diff --git a/rss2email/error.py b/rss2email/error.py
index 49a1c93..9567b32 100644
--- a/rss2email/error.py
+++ b/rss2email/error.py
@@ -153,12 +153,20 @@ class InvalidFeedConfig (FeedError):
 
 
 class InvalidFeedName (InvalidFeedConfig):
-    def __init__(self, name, **kwargs):
-        message = "invalid feed name '{}'".format(name)
+    def __init__(self, name, message=None, **kwargs):
+        if not message:
+            message = 'invalid feed name {!r}'.format(name)
         super(InvalidFeedName, self).__init__(
             setting='name', message=message, **kwargs)
 
 
+class DuplicateFeedName (InvalidFeedName):
+    def __init__(self, name, **kwargs):
+        message = 'duplicate feed name {!r}'.format(name)
+        super(DuplicateFeedName, self).__init__(
+            name=name, message=message, **kwargs)
+
+
 class ProcessingError (FeedError):
     def __init__(self, parsed, feed, message=None, **kwargs):
         if message is None:
diff --git a/rss2email/feeds.py b/rss2email/feeds.py
index edd5f66..5b5a34c 100644
--- a/rss2email/feeds.py
+++ b/rss2email/feeds.py
@@ -388,15 +388,22 @@ class Feeds (list):
         feed-0 (None -> a@b.com)
         >>> print(feeds.new_feed())
         feed-1 (None -> a@b.com)
+        >>> print(feeds.new_feed(name='feed-1'))
+        Traceback (most recent call last):
+          ...
+        rss2email.error.DuplicateFeedName: duplicate feed name 'feed-1'
         """
+        feed_names = [feed.name for feed in self]
         if name is None:
             i = 0
             while True:
                 name = '{}{}'.format(prefix, i)
-                feed_names = [feed.name for feed in self]
                 if name not in feed_names:
                     break
                 i += 1
+        elif name in feed_names:
+            feed = self[name]
+            raise _error.DuplicateFeedName(name=feed.name, feed=feed)
         feed = _feed.Feed(name=name, **kwargs)
         self.append(feed)
         return feed
-- 
2.26.2