Add attached patches to message view

Also let the user expand/collapse them by clicking.

Author: AndersAstrand

app/assets/stylesheets/components/messages.css

@@ -224,18 +224,23 @@
 
 .attachment-info {
   display: flex;
-  gap: var(--spacing-3);
   align-items: center;
   font-size: var(--font-size-sm);
 }
 
+summary.attachment-info {
+  cursor: pointer;
+  display: list-item;
+}
+
 .filename {
   font-weight: var(--font-weight-medium);
   color: var(--color-text-primary);
 }
 
 .content-type {
   color: var(--color-text-muted);
+  margin-left: var(--spacing-3);
 }
 
 .import-metadata {

app/views/topics/_message.html.slim

@@ -41,10 +41,19 @@
       .message-attachments
         h4 Attachments:
         - message.attachments.each do |attachment|
-          .attachment
-            .attachment-info
-              span.filename = attachment.file_name
-              span.content-type = attachment.content_type if attachment.content_type
+          - if attachment.patch?
+            details class="attachment"
+              summary class="attachment-info"
+                span.filename = attachment.file_name
+                span.content-type = attachment.content_type if attachment.content_type
+              pre class="attachment-content"
+                code class="language-diff"
+                  = attachment.decoded_body
+          - else
+            .attachment
+              .attachment-info
+                span.filename = attachment.file_name
+                span.content-type = attachment.content_type if attachment.content_type
 
   - if message.import_log.present?
     .import-metadata