From 52f15bc1134ba2477f8461dd13c02f275f3d9660 Mon Sep 17 00:00:00 2001
From: Ricardo Wurmus <rekado@elephly.net>
Date: Sat, 24 Dec 2022 23:17:32 +0100
Subject: Truncate very long message parts.

---
 assets/mumi.scss        | 10 ++++++++++
 mumi/web/view/utils.scm | 21 +++++++++++++++++----
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/assets/mumi.scss b/assets/mumi.scss
index 22925ab..6912a88 100644
--- a/assets/mumi.scss
+++ b/assets/mumi.scss
@@ -537,6 +537,16 @@ details {
     display: none;
 }
 
+.truncation-notice:before {
+	display: block;
+	background: linear-gradient(#00000000,var(--card-background-color));
+	height: 20rem;
+	width: 100%;
+	position: relative;
+	content: " ";
+	margin-top: -20rem;
+}
+
 .message div.line {
     white-space: pre-wrap;
     font-family: monospace;
diff --git a/mumi/web/view/utils.scm b/mumi/web/view/utils.scm
index 7ab5ab5..1ce7b64 100644
--- a/mumi/web/view/utils.scm
+++ b/mumi/web/view/utils.scm
@@ -237,6 +237,7 @@ V8.5a.5.5 0 011 0V12a2 2 0 01-2 2H2a2 2 0 01-2-2V8.5A.5.5 0 01.5 8z")) "")
   "Convenience procedure to render MESSAGE (part of bug with number
 BUG-NUM), even when it is a multipart message.  Do not prettify
 lines when PLAIN? is #T."
+  (define truncation-limit 20000)
   (define (display-multipart-chunk headers body path)
     (define (attachment-url)
       (string-append "/issue/"
@@ -265,7 +266,10 @@ lines when PLAIN? is #T."
            (attachment-name
             (or (and=> (assoc-ref headers 'content-disposition)
                        (cut assoc-ref <> 'filename))
-                "file")))
+                "file"))
+           (truncate-text?
+            (and (not attachment?)
+                 (> (string-length body) truncation-limit))))
       (cond
        ((or html? hide-attachment?)
         `(div (@ (class "attachment"))
@@ -293,9 +297,18 @@ lines when PLAIN? is #T."
               (div (@ (class "download-part"))
                    (a (@ (href ,(attachment-url)))
                       ,download-icon))
-              ,(if plain?
-                   `(pre (@ (class "ugly-body")) ,body)
-                   (prettify body message-number)))))))
+              ,(cond
+                (plain?
+                 `(pre (@ (class "ugly-body")) ,body))
+                (truncate-text?
+                 `(,(prettify (string-take body truncation-limit) message-number)
+                   (div
+                    (@ (class "truncation-notice"))
+                    "This message was truncated. "
+                    (a (@ (href ,(attachment-url)))
+                       "Download the full message here."))))
+                (else
+                 (prettify body message-number))))))))
   (define (display-mime-entity entity . path)
     (match entity
       (($ <mime-entity> headers (? string? body))
-- 
cgit v1.2.3