Let an untouched Save keep the name it was already showing

Yattee/Views/Settings/AccountRenameAlert.swift

@@ -22,6 +22,51 @@ struct AccountRenameRequest: Identifiable {
 
     /// What the field is prefilled with: the label the row is showing now.
     let initialText: String
+
+    /// Whether that prefill is a name the user chose, as opposed to the label
+    /// the account falls back to on this device. It is what tells an untouched
+    /// save to keep the name from one that must not publish a device-local
+    /// fallback — see `DataContextValidator.renamedDisplayName`.
+    let hasUserSetLabel: Bool
+}
+
+extension AccountRenameRequest {
+    /// The request for an account that still resolves through a source.
+    ///
+    /// The single place the alert's strings are derived, so both surfaces that
+    /// offer Rename ask the validator the same two questions: what the row is
+    /// showing, and what clearing the field goes back to.
+    @MainActor
+    static func forAccount(_ account: Account, resolvedBy validator: DataContextValidator) -> Self {
+        Self(
+            id: account.id,
+            defaultName: validator.defaultDisplayName(for: account),
+            initialText: validator.displayName(for: account),
+            hasUserSetLabel: account.hasUserSetDisplayName
+        )
+    }
+
+    /// The request for an account with no source to resolve through.
+    ///
+    /// The fallback is the caller's to name: the validator's last resort for an
+    /// account whose instance is gone is the words "Source missing", which is a
+    /// diagnosis and not a name to offer the field.
+    static func forAccount(_ account: Account, fallingBackTo defaultName: String) -> Self {
+        Self(
+            id: account.id,
+            defaultName: defaultName,
+            initialText: account.displayName ?? "",
+            hasUserSetLabel: account.hasUserSetDisplayName
+        )
+    }
+}
+
+extension Account {
+    /// Whether the account carries a label the user chose. An empty string is
+    /// no more a name than `nil` is, and both arrive here from old records.
+    var hasUserSetDisplayName: Bool {
+        !(displayName ?? "").isEmpty
+    }
 }
 
 /// The rename alert, shared by every screen that lists accounts.
@@ -40,8 +85,14 @@ private struct AccountRenameAlertModifier: ViewModifier {
             // Keyed on the ID rather than on the request: the prefill has to be
             // in place before the alert's field is built, and re-entering the
             // same row is the only time the text should be reset.
+            //
+            // Seeded only when a request appears, never blanked when one goes
+            // away. Dismissal sets the request to nil while the alert's buttons
+            // are still live, and Save reads this text when it runs — blanking
+            // here would let the two race, with an emptied field committing as
+            // "clear the name".
             .onChange(of: request?.id) { _, _ in
-                text = request?.initialText ?? ""
+                if let request { text = request.initialText }
             }
             .alert(
                 String(localized: "accounts.rename.title"),
@@ -56,7 +107,11 @@ private struct AccountRenameAlertModifier: ViewModifier {
                 Button(String(localized: "common.save")) {
                     onCommit(
                         pending.id,
-                        DataContextValidator.renamedDisplayName(text, fallingBackTo: pending.defaultName)
+                        DataContextValidator.renamedDisplayName(
+                            text,
+                            prefilledWith: pending.initialText,
+                            hasUserSetLabel: pending.hasUserSetLabel
+                        )
                     )
                 }
 

Yattee/Views/Settings/AccountsListView.swift

@@ -349,18 +349,10 @@ struct AccountsListView: View {
     /// prefill a field with.
     private func makeRenameRequest(for account: Account, instance: Instance?) -> AccountRenameRequest {
         guard instance != nil, let validator = appEnvironment?.dataContextValidator else {
-            return AccountRenameRequest(
-                id: account.id,
-                defaultName: String(localized: "accounts.orphan.unnamed"),
-                initialText: account.displayName ?? ""
-            )
+            return .forAccount(account, fallingBackTo: String(localized: "accounts.orphan.unnamed"))
         }
 
-        return AccountRenameRequest(
-            id: account.id,
-            defaultName: validator.defaultDisplayName(for: account),
-            initialText: validator.displayName(for: account)
-        )
+        return .forAccount(account, resolvedBy: validator)
     }
 
     private func status(for account: Account) -> AccountStatus {

Yattee/Views/Settings/InstanceAccountsSection.swift

@@ -195,13 +195,16 @@ struct InstanceAccountsSection: View {
     }
 
     /// What the rename field starts on, and what clearing it goes back to.
+    ///
+    /// The section always has its instance, so the only reason to name the
+    /// fallback here is a missing environment, where the row's own label is
+    /// already the instance's.
     private func makeRenameRequest(for account: Account) -> AccountRenameRequest {
-        AccountRenameRequest(
-            id: account.id,
-            defaultName: appEnvironment?.dataContextValidator.defaultDisplayName(for: account)
-                ?? instance.displayName,
-            initialText: displayName(for: account)
-        )
+        guard let validator = appEnvironment?.dataContextValidator else {
+            return .forAccount(account, fallingBackTo: instance.displayName)
+        }
+
+        return .forAccount(account, resolvedBy: validator)
     }
 
     private func status(for account: Account) -> AccountStatus {