From a9c80b90f65621a2b5b72d65ff2865c5c92be774 Mon Sep 17 00:00:00 2001
From: Tobias Fella <fella@posteo.de>
Date: Sun, 23 Oct 2022 15:55:39 +0200
Subject: [PATCH] Show old display name for name change events

BUG: 457664
---
 .../NeoChat/Component/Timeline/StateDelegate.qml   |  2 +-
 src/messageeventmodel.cpp                          | 14 ++++++++++++++
 src/messageeventmodel.h                            |  3 ++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/imports/NeoChat/Component/Timeline/StateDelegate.qml b/imports/NeoChat/Component/Timeline/StateDelegate.qml
index f54c3a92b..be845b353 100644
--- a/imports/NeoChat/Component/Timeline/StateDelegate.qml
+++ b/imports/NeoChat/Component/Timeline/StateDelegate.qml
@@ -96,7 +96,7 @@ Control {
             Layout.preferredHeight: icon.height
             wrapMode: Text.WordWrap
             textFormat: Text.RichText
-            text: `<style>a {text-decoration: none;}</style><a href="https://matrix.to/#/${author.id}" style="color: ${author.color}">${currentRoom.htmlSafeMemberName(author.id)}</a> ${aggregateDisplay}`
+            text: `<style>a {text-decoration: none;}</style><a href="https://matrix.to/#/${author.id}" style="color: ${author.color}">${model.authorDisplayName}</a> ${aggregateDisplay}`
             onLinkActivated: userDetailDialog.createObject(ApplicationWindow.overlay, {room: currentRoom, user: author.object, displayName: author.displayName, avatarMediaId: author.avatarMediaId, avatarUrl: author.avatarUrl}).open()
         }
     }
diff --git a/src/messageeventmodel.cpp b/src/messageeventmodel.cpp
index b73b9c6b2..6f5234834 100644
--- a/src/messageeventmodel.cpp
+++ b/src/messageeventmodel.cpp
@@ -60,6 +60,7 @@ QHash<int, QByteArray> MessageEventModel::roleNames() const
     roles[MediaUrlRole] = "mediaUrl";
     roles[VerifiedRole] = "verified";
     roles[DisplayNameForInitialsRole] = "displayNameForInitials";
+    roles[AuthorDisplayNameRole] = "authorDisplayName";
     return roles;
 }
 
@@ -840,6 +841,19 @@ QVariant MessageEventModel::data(const QModelIndex &idx, int role) const
         return user->displayname(m_currentRoom).remove(QStringLiteral(" (%1)").arg(user->id()));
     }
 
+    if (role == AuthorDisplayNameRole) {
+        if (!evt.unsignedJson()["prev_content"]["displayname"].isNull()) {
+            auto previousDisplayName = evt.unsignedJson()["prev_content"]["displayname"].toString().toHtmlEscaped();
+            if (previousDisplayName.isEmpty()) {
+                previousDisplayName = evt.senderId();
+            }
+            return previousDisplayName;
+        } else {
+            auto author = static_cast<NeoChatUser *>(isPending ? m_currentRoom->localUser() : m_currentRoom->user(evt.senderId()));
+            m_currentRoom->htmlSafeMemberName(author->id());
+        }
+    }
+
     return {};
 }
 
diff --git a/src/messageeventmodel.h b/src/messageeventmodel.h
index b371ffad9..387c6ce83 100644
--- a/src/messageeventmodel.h
+++ b/src/messageeventmodel.h
@@ -48,9 +48,10 @@ public:
         EventResolvedTypeRole,
         AuthorIdRole,
         VerifiedRole,
-
         // Sender's displayname, always without the matrix id
         DisplayNameForInitialsRole,
+        // The displayname for the event's sender; for name change events, the old displayname
+        AuthorDisplayNameRole,
         LastRole, // Keep this last
     };
     Q_ENUM(EventRoles)