From 59b8f85c6369514d6a19c76d04de3177185adc83 Mon Sep 17 00:00:00 2001
From: Vishnu Ks <yo@vishnuks.com>
Date: Sat, 24 Feb 2018 01:47:29 +0530
Subject: [PATCH] bugdown: Do only image preview if relative URL.

---
 zerver/lib/bugdown/__init__.py  | 11 +++++++++--
 zerver/tests/test_link_embed.py | 11 +++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/zerver/lib/bugdown/__init__.py b/zerver/lib/bugdown/__init__.py
index 81b2c09218..6ee41af85e 100644
--- a/zerver/lib/bugdown/__init__.py
+++ b/zerver/lib/bugdown/__init__.py
@@ -823,10 +823,12 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
             if uncle_link not in parent_links:
                 return insertion_index
 
+    def is_absolute_url(self, url: Text) -> bool:
+        return bool(urllib.parse.urlparse(url).netloc)
+
     def run(self, root: Element) -> None:
         # Get all URLs from the blob
         found_urls = walk_tree_with_family(root, self.get_url_data)
-
         if len(found_urls) == 0 or len(found_urls) > self.INLINE_PREVIEW_LIMIT_PER_MESSAGE:
             return
 
@@ -834,8 +836,13 @@ class InlineInterestingLinkProcessor(markdown.treeprocessors.Treeprocessor):
 
         for found_url in found_urls:
             (url, text) = found_url.result
-            dropbox_image = self.dropbox_image(url)
+            if not self.is_absolute_url(url):
+                if self.is_image(url):
+                    self.handle_image_inlining(root, found_url)
+                # We don't have a strong use case for doing url preview for relative links.
+                continue
 
+            dropbox_image = self.dropbox_image(url)
             if dropbox_image is not None:
                 class_attr = "message_inline_ref"
                 is_image = dropbox_image["is_image"]
diff --git a/zerver/tests/test_link_embed.py b/zerver/tests/test_link_embed.py
index 72ce40015d..9c604eb54d 100644
--- a/zerver/tests/test_link_embed.py
+++ b/zerver/tests/test_link_embed.py
@@ -313,6 +313,17 @@ class PreviewTestCase(ZulipTestCase):
         msg = self._send_message_with_test_org_url(sender_email=self.example_email('prospero'), queue_should_run=False)
         self.assertEqual(msg.rendered_content, without_preview)
 
+    @override_settings(INLINE_URL_EMBED_PREVIEW=True)
+    def test_inline_relative_url_embed_preview(self) -> None:
+        # Relative urls should not be sent for url preview.
+        with mock.patch('zerver.lib.actions.queue_json_publish') as patched:
+            self.send_personal_message(
+                self.example_email('prospero'),
+                self.example_email('cordelia'),
+                content="http://zulip.testserver/api/",
+            )
+            patched.assert_not_called()
+
     def test_inline_url_embed_preview_with_relative_image_url(self) -> None:
         with_preview_relative = '<p><a href="http://test.org/" target="_blank" title="http://test.org/">http://test.org/</a></p>\n<div class="message_embed"><a class="message_embed_image" href="http://test.org/" style="background-image: url(http://test.org/images/rock.jpg)" target="_blank"></a><div class="data-container"><div class="message_embed_title"><a href="http://test.org/" target="_blank" title="The Rock">The Rock</a></div><div class="message_embed_description">Description text</div></div></div>'
         # Try case where the opengraph image is a relative url.