Don't overwrite image title and links when "itunes:image" is present

CONTRIBUTORS.rst

@@ -28,3 +28,4 @@ bug report!
 * `Aaron Swartz <http://www.aaronsw.com/>`_
 * `Jakub Wilk <http://jwilk.net/>`_
 * `Nestor Rodriguez <https://github.com/n3s7or>`_
+* `Niko Abeler <https://github.com/h4kor>`_

feedparser/namespaces/itunes.py

@@ -91,10 +91,12 @@ def _start_itunes_category(self, attrs_d):
 
     def _start_itunes_image(self, attrs_d):
         self.push('itunes_image', 0)
-        if attrs_d.get('href'):
-            self._get_context()['image'] = FeedParserDict({'href': attrs_d.get('href')})
-        elif attrs_d.get('url'):
-            self._get_context()['image'] = FeedParserDict({'href': attrs_d.get('url')})
+        href = attrs_d.get('href', attrs_d.get('url', None))
+        if href:
+            if "image" not in self._get_context():
+                self._get_context()['image'] = FeedParserDict({'href': href})
+            else:
+                self._get_context()['image']['href'] = href
     _start_itunes_link = _start_itunes_image
 
     def _end_itunes_block(self):

tests/entities/image_and_itunes_image.xml

@@ -0,0 +1,14 @@
+<!--
+Description: itunes:image does not overwrite existing image title and link
+Expect:      feed['image']["title"] == 'Image Test' and feed['image']["links"][0]["href"] == 'https://example.com'
+-->
+<rss>
+    <channel>
+        <image>
+            <url>https://example.com/image.png</url>
+            <title>Image Test</title>
+            <link>https://example.com</link>
+        </image>
+        <itunes:image href="https://example.com/image.png"/>
+    </channel>
+</rss>