From 92b66ef68d0b8464b6a7b000a140bb8bba6e08b6 Mon Sep 17 00:00:00 2001
From: "Evgeny @ SimpleX Chat"
 <259188159+evgeny-simplex@users.noreply.github.com>
Date: Fri, 10 Jul 2026 22:21:09 +0000
Subject: [PATCH] core: preserve domain during group handshake

---
 src/Simplex/Chat/Store/Groups.hs | 6 +++++-
 src/Simplex/Chat/View.hs         | 4 +++-
 tests/ChatTests/Names.hs         | 5 +++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/Simplex/Chat/Store/Groups.hs b/src/Simplex/Chat/Store/Groups.hs
index b10b7ad239..b4cdf91b8e 100644
--- a/src/Simplex/Chat/Store/Groups.hs
+++ b/src/Simplex/Chat/Store/Groups.hs
@@ -2721,7 +2721,11 @@ updateGroupProfile db user@User {userId} g@GroupInfo {groupId, localDisplayName,
     -- group_domain is owned by publicGroup; when the incoming profile has no publicGroup (a business, whose domain
     -- is set out-of-band) the CASE leaves the stored group_domain unchanged instead of clearing it.
     updateGroupProfile_ currentTs =
-      let (groupWebPage_, groupDomain_, domainWebPage_, allowEmbedding_, groupDomainProof_) = publicGroupAccessRow publicGroup
+      -- the wire carries the domain but not its signed proof (the group's link is authoritative for the claim), so
+      -- keep the stored proof on an unchanged domain instead of overwriting it with the empty incoming one, the same
+      -- way updateContactProfile preserves contactDomain's proof
+      let (groupWebPage_, groupDomain_, domainWebPage_, allowEmbedding_, _) = publicGroupAccessRow publicGroup
+          groupDomainProof_ = if claimChanged then Nothing else oldPublicGroup >>= publicGroupAccess >>= groupDomainClaim >>= proof
        in DB.execute
             db
             [sql|
diff --git a/src/Simplex/Chat/View.hs b/src/Simplex/Chat/View.hs
index 0edfff6d29..36dce4cfc5 100644
--- a/src/Simplex/Chat/View.hs
+++ b/src/Simplex/Chat/View.hs
@@ -1827,10 +1827,12 @@ viewContactInfo ct@Contact {contactId, profile = LocalProfile {localAlias, conta
     <> viewCustomData customData
 
 viewGroupInfo :: GroupInfo -> [StyledString]
-viewGroupInfo gInfo@GroupInfo {groupId, uiThemes, customData, groupSummary = GroupSummary {currentMembers, publicMemberCount}} =
+viewGroupInfo gInfo@GroupInfo {groupId, businessChat, groupDomainVerified, uiThemes, customData, groupSummary = GroupSummary {currentMembers, publicMemberCount}} =
   [ "group ID: " <> sShow groupId,
     memberCountLine
   ]
+    -- a business presents as a contact, so its verified domain is shown as an @-name
+    <> simplexDomainLine NTContact (businessDomain =<< businessChat) groupDomainVerified
     <> viewUITheme uiThemes
     <> viewCustomData customData
   where
diff --git a/tests/ChatTests/Names.hs b/tests/ChatTests/Names.hs
index 1de347e026..28f56c6fd1 100644
--- a/tests/ChatTests/Names.hs
+++ b/tests/ChatTests/Names.hs
@@ -239,5 +239,10 @@ testConnectByNameBusinessAndChannel ps = withSmpServerAndNames $ \reg ->
         bob ##> "/_connect plan 1 @biz.simplex resolve=never"
         bob <## "business address: known business #alice"
         bob <## "use #alice <message> to send messages"
+        -- the business's verified domain survives the handshake and is shown in group info
+        bob ##> "/i #alice"
+        bob <## "group ID: 1"
+        bob <## "current members: 2"
+        bob <## "SimpleX name: @biz.simplex (verified)"
   where
     bizName = SimplexNameInfo NTContact (SimplexDomain TLDSimplex "biz" [])