Prevent a crash when buddy alias is NULL due to funny namey

client-utils.cpp

@@ -234,16 +234,7 @@ void updatePrivateChat(TdAccountData &account, const td::td_api::chat &chat, con
                                  PURPLE_MESSAGE_SYSTEM, time(NULL));
         }
     } else {
-        const char *oldName = purple_buddy_get_alias_only(buddy);
+        purple_blist_alias_buddy(buddy, chat.title_.c_str());
-        if (chat.title_ != oldName) {
-            purple_debug_misc(config::pluginId, "Renaming buddy %s '%s' to '%s'\n",
-                                purpleUserName.c_str(), oldName, chat.title_.c_str());
-            /*PurpleGroup *group = purple_buddy_get_group(buddy);
-            purple_blist_remove_buddy(buddy);
-            buddy = purple_buddy_new(m_account, purpleUserName.c_str(), chat.title_.c_str());
-            purple_blist_add_buddy(buddy, NULL, group, NULL);*/
-            purple_blist_alias_buddy(buddy, chat.title_.c_str());
-        }
 
         const char *oldPhotoIdStr = purple_blist_node_get_string(PURPLE_BLIST_NODE(buddy), BuddyOptions::ProfilePhotoId);
         int64_t     oldPhotoId    = 0;

test/libpurple-mock.cpp

@@ -208,12 +208,23 @@ void purple_blist_remove_buddy(PurpleBuddy *buddy)
     purple_buddy_destroy(buddy);
 }
 
+static gboolean
+purple_strings_are_different(const char *one, const char *two)
+{
+        return !((one && two && g_utf8_collate(one, two) == 0) ||
+                        ((one == NULL || *one == '\0') && (two == NULL || *two == '\0')));
+}
+
 void purple_blist_alias_buddy(PurpleBuddy *buddy, const char *alias)
 {
     ASSERT_NE(nullptr, buddy);
-    free(buddy->alias);
+
-    buddy->alias = strdup(alias);
+    // Similar to real libpurple
-    EVENT(AliasBuddyEvent, buddy->name, alias);
+    if (purple_strings_are_different(buddy->alias, alias)) {
+        free(buddy->alias);
+        buddy->alias = strdup(alias);
+        EVENT(AliasBuddyEvent, buddy->name, alias);
+    }
 }
 
 static char *getChatName(const PurpleChat *chat)
@@ -288,7 +299,7 @@ PurpleBuddy *purple_buddy_new(PurpleAccount *account, const char *name, const ch
 
     buddy->account = account;
     buddy->name = strdup(name);
-    buddy->alias = strdup(alias);
+    buddy->alias = alias ? strdup(alias) : NULL;
     buddy->node.parent = NULL;
     newNode(buddy->node, PURPLE_BLIST_BUDDY_NODE);
 

test/login-test.cpp

@@ -374,6 +374,7 @@ TEST_F(LoginTest, BuddyRenamedByServer)
 
     tgl.update(make_object<updateChatTitle>(chatIds[0], "New Name"));
     prpl.verifyEvents(AliasBuddyEvent(purpleUserName(0), "New Name"));
+
     object_ptr<updateUser> updateUser = standardUpdateUser(0);
     updateUser->user_->first_name_ = "New";
     updateUser->user_->last_name_ = "Name";

test/private-chat-test.cpp

@@ -1044,3 +1044,24 @@ TEST_F(PrivateChatTest, WriteToUnknownUser)
         )
     );
 }
+
+TEST_F(PrivateChatTest, BuddyWithNullAlias)
+{
+    PurpleBuddy *buddy = purple_buddy_new(account, purpleUserName(0).c_str(), NULL);
+    purple_blist_add_buddy(buddy, NULL, &standardPurpleGroup, NULL);
+    prpl.discardEvents();
+
+    login(
+        {standardUpdateUser(0), standardPrivateChat(0), makeUpdateChatListMain(chatIds[0])},
+        make_object<users>(1, std::vector<int32_t>(1, userIds[0])),
+        make_object<chats>(std::vector<int64_t>(1, chatIds[0])),
+        {}, {},
+        {
+            std::make_unique<ConnectionSetStateEvent>(connection, PURPLE_CONNECTED),
+            std::make_unique<AliasBuddyEvent>(purpleUserName(0), userFirstNames[0] + " " + userLastNames[0]),
+            std::make_unique<UserStatusEvent>(account, purpleUserName(0), PURPLE_STATUS_OFFLINE),
+            std::make_unique<AccountSetAliasEvent>(account, selfFirstName + " " + selfLastName),
+            std::make_unique<ShowAccountEvent>(account)
+        }
+    );
+}

test/purple-events.h

@@ -132,10 +132,14 @@ struct AddBuddyEvent: PurpleEvent {
     PurpleGroup     *group;
     PurpleBlistNode *node;
 
+    AddBuddyEvent(const std::string &username, const char *alias, PurpleAccount *account,
+                  PurpleContact *contact, PurpleGroup *group, PurpleBlistNode *node)
+    : PurpleEvent(PurpleEventType::AddBuddy), username(username), alias(alias ? alias : ""),
+      account(account), contact(contact), group(group), node(node) {}
+
     AddBuddyEvent(const std::string &username, const std::string &alias, PurpleAccount *account,
                   PurpleContact *contact, PurpleGroup *group, PurpleBlistNode *node)
-    : PurpleEvent(PurpleEventType::AddBuddy), username(username), alias(alias), account(account),
+    : AddBuddyEvent(username, alias.c_str(), account, contact, group, node) {}
-      contact(contact), group(group), node(node) {}
 };
 
 struct AddChatEvent: PurpleEvent {