From 533f4fbb4ae13dcd384d0202d7c8349a6bb110c3 Mon Sep 17 00:00:00 2001
From: link2xt <link2xt@testrun.org>
Date: Wed, 21 Jan 2026 08:58:44 +0000
Subject: [PATCH] add API to opt out of truncating long messages

---
 deltachat-jsonrpc/src/api.rs | 14 ++++++++++++--
 src/context.rs               | 12 ++++++++++++
 src/message.rs               | 18 ++++++++++++++++++
 src/tools.rs                 |  5 ++++-
 4 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/deltachat-jsonrpc/src/api.rs b/deltachat-jsonrpc/src/api.rs
index ffdb16c6e..e52aea152 100644
--- a/deltachat-jsonrpc/src/api.rs
+++ b/deltachat-jsonrpc/src/api.rs
@@ -23,8 +23,9 @@ use deltachat::ephemeral::Timer;
 use deltachat::imex;
 use deltachat::location;
 use deltachat::message::{
-    self, delete_msgs_ex, get_existing_msg_ids, get_msg_read_receipt_count, get_msg_read_receipts,
-    markseen_msgs, Message, MessageState, MsgId, Viewtype,
+    self, delete_msgs_ex, dont_truncate_long_messages, get_existing_msg_ids,
+    get_msg_read_receipt_count, get_msg_read_receipts, markseen_msgs, Message, MessageState, MsgId,
+    Viewtype,
 };
 use deltachat::peer_channels::{
     leave_webxdc_realtime, send_webxdc_realtime_advertisement, send_webxdc_realtime_data,
@@ -1434,6 +1435,15 @@ impl CommandApi {
         MsgId::new(message_id).get_html(&ctx).await
     }
 
+    /// Opt out of truncating long messages when loading.
+    ///
+    /// Should be used by the UIs that can handle long text messages.
+    async fn dont_truncate_long_messages(&self, account_id: u32) -> Result<()> {
+        let ctx = self.get_context(account_id).await?;
+        dont_truncate_long_messages(&ctx);
+        Ok(())
+    }
+
     /// get multiple messages in one call,
     /// if loading one message fails the error is stored in the result object in it's place.
     ///
diff --git a/src/context.rs b/src/context.rs
index adcb3b2a7..bea13148a 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -227,7 +227,18 @@ impl WeakContext {
 pub struct InnerContext {
     /// Blob directory path
     pub(crate) blobdir: PathBuf,
+
     pub(crate) sql: Sql,
+
+    /// True if long text messages should be truncated
+    /// and full message HTML added.
+    ///
+    /// This should be set by the UIs that cannot handle
+    /// long messages but can display HTML messages.
+    ///
+    /// Ignored for bots, bots never get truncated messages.
+    pub(crate) truncate_long_messages: AtomicBool,
+
     pub(crate) smeared_timestamp: SmearedTimestamp,
     /// The global "ongoing" process state.
     ///
@@ -491,6 +502,7 @@ impl Context {
             blobdir,
             running_state: RwLock::new(Default::default()),
             sql: Sql::new(dbfile),
+            truncate_long_messages: AtomicBool::new(true),
             smeared_timestamp: SmearedTimestamp::new(),
             oauth2_mutex: Mutex::new(()),
             wrong_pw_warning_mutex: Mutex::new(()),
diff --git a/src/message.rs b/src/message.rs
index 99db9eb35..2e8674427 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -4,6 +4,7 @@ use std::collections::BTreeSet;
 use std::collections::HashSet;
 use std::path::{Path, PathBuf};
 use std::str;
+use std::sync::atomic::Ordering;
 
 use anyhow::{Context as _, Result, ensure, format_err};
 use deltachat_contact_tools::{VcardContact, parse_vcard};
@@ -2398,5 +2399,22 @@ impl Viewtype {
     }
 }
 
+/// Opt out of truncating long messages.
+///
+/// After calling this function, long messages
+/// will not be truncated during loading.
+///
+/// UIs should call this function if they
+/// can handle long messages by cutting them
+/// and displaying "Show full message" option.
+///
+/// Has no effect for bots which never
+/// truncate messages when loading.
+pub fn dont_truncate_long_messages(context: &Context) {
+    context
+        .truncate_long_messages
+        .store(false, Ordering::Relaxed);
+}
+
 #[cfg(test)]
 mod message_tests;
diff --git a/src/tools.rs b/src/tools.rs
index 30ec3ee08..f0cf1ce58 100644
--- a/src/tools.rs
+++ b/src/tools.rs
@@ -9,6 +9,7 @@ use std::mem;
 use std::ops::{AddAssign, Deref};
 use std::path::{Path, PathBuf};
 use std::str::from_utf8;
+use std::sync::atomic::Ordering;
 // If a time value doesn't need to be sent to another host, saved to the db or otherwise used across
 // program restarts, a monotonically nondecreasing clock (`Instant`) should be used. But as
 // `Instant` may use `libc::clock_gettime(CLOCK_MONOTONIC)`, e.g. on Android, and does not advance
@@ -139,7 +140,9 @@ pub(crate) fn truncate_by_lines(
 ///
 /// Returns the resulting text and a bool telling whether a truncation was done.
 pub(crate) async fn truncate_msg_text(context: &Context, text: String) -> Result<(String, bool)> {
-    if context.get_config_bool(Config::Bot).await? {
+    if !context.truncate_long_messages.load(Ordering::Relaxed)
+        || context.get_config_bool(Config::Bot).await?
+    {
         return Ok((text, false));
     }
     // Truncate text if it has too many lines