Let an untouched Save keep the name it was already showing

Yattee/Core/AccountsManager.swift

@@ -230,8 +230,16 @@ final class AccountsManager {
         pendingMarkerUploads.insert(instanceID)
     }
 
+    /// Stores the account's user-set label, or clears it with `nil`.
+    ///
+    /// A save that changes nothing is dropped rather than written. The rename
+    /// field is prefilled, so "Save" without an edit is the ordinary way out of
+    /// the alert — and every write here stamps `updatedAt` and queues an
+    /// upload, which under last-write-wins would let that idle tap overwrite a
+    /// peer's genuine rename that has not reached this device yet.
     func updateDisplayName(_ displayName: String?, for accountID: UUID) {
         guard let index = accounts.firstIndex(where: { $0.id == accountID }) else { return }
+        guard accounts[index].displayName != displayName else { return }
         accounts[index].displayName = displayName
         accounts[index].updatedAt = Date()
         pendingUploads.insert(accountID)

Yattee/Services/Subscriptions/DataContextValidator.swift

@@ -239,14 +239,32 @@ final class DataContextValidator {
     /// What a rename field's contents mean once the user is done typing.
     ///
     /// `nil` clears the user-set label and hands the account back to
-    /// `defaultDisplayName`. An empty field says that outright — and so does
-    /// typing exactly the name the account already falls back to. The field
-    /// starts prefilled with the label the row is showing, so saving it
-    /// untouched must not turn a *device-local* fallback into a synced label
-    /// that every other device is then made to display.
-    static func renamedDisplayName(_ input: String, fallingBackTo defaultName: String) -> String? {
+    /// `defaultDisplayName`; anything else is stored as typed.
+    ///
+    /// The question the field cannot answer on its own is what an *untouched*
+    /// save means. The field starts prefilled with the label the row shows, and
+    /// on an account with no user-set label that label is device-local — the
+    /// login identifier only exists where the credential does. Saving it
+    /// unedited must not turn one device's fallback into a synced label every
+    /// other device is then made to display, so that case clears instead.
+    ///
+    /// The test is editedness, never equality with the default: on a second
+    /// device the string that device happens to fall back to is a perfectly
+    /// ordinary name to *choose*, and typing it has to store and sync like any
+    /// other. An unedited save on an account that already carries a label
+    /// re-states that label, which the manager then drops as a no-op — the name
+    /// stays, rather than being silently cleared by a tap that changed nothing.
+    static func renamedDisplayName(
+        _ input: String,
+        prefilledWith prefill: String,
+        hasUserSetLabel: Bool
+    ) -> String? {
         let trimmed = input.trimmingCharacters(in: .whitespacesAndNewlines)
-        guard !trimmed.isEmpty, trimmed != defaultName else { return nil }
+        guard !trimmed.isEmpty else { return nil }
+
+        let wasEdited = trimmed != prefill.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard wasEdited || hasUserSetLabel else { return nil }
+
         return trimmed
     }
 }

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 {

YatteeTests/AccountsScreenTests.swift

@@ -490,29 +490,166 @@ struct AccountRenameTests {
     @Test("A typed name replaces the fallback")
     func typedNameIsStored() {
         #expect(
-            DataContextValidator.renamedDisplayName("  Main i01 ", fallingBackTo: "i01") == "Main i01"
+            DataContextValidator.renamedDisplayName(
+                "  Main i01 ",
+                prefilledWith: "i01",
+                hasUserSetLabel: false
+            ) == "Main i01"
         )
     }
 
     @Test("An empty field clears the label")
     func emptyClearsTheLabel() {
-        #expect(DataContextValidator.renamedDisplayName("", fallingBackTo: "i01") == nil)
-        #expect(DataContextValidator.renamedDisplayName("   \n ", fallingBackTo: "i01") == nil)
+        for hasLabel in [true, false] {
+            #expect(
+                DataContextValidator.renamedDisplayName(
+                    "",
+                    prefilledWith: "i01",
+                    hasUserSetLabel: hasLabel
+                ) == nil
+            )
+            #expect(
+                DataContextValidator.renamedDisplayName(
+                    "   \n ",
+                    prefilledWith: "Main i01",
+                    hasUserSetLabel: hasLabel
+                ) == nil
+            )
+        }
     }
 
-    @Test("Saving the prefilled fallback untouched sets no name at all")
+    @Test("Saving an unnamed account's prefill untouched sets no name at all")
     func unchangedFallbackIsNotStored() {
-        // The field starts on the label the row is showing, and that label can
-        // be device-local — the login identifier only exists where the
-        // credential does. Storing it would publish one device's fallback to
-        // every other device as if the user had chosen it.
-        #expect(DataContextValidator.renamedDisplayName("i01", fallingBackTo: "i01") == nil)
+        // The field starts on the label the row is showing, and on an account
+        // with no user-set label that is device-local — the login identifier
+        // only exists where the credential does. Storing it would publish one
+        // device's fallback to every other device as if the user had chosen it.
         #expect(
             DataContextValidator.renamedDisplayName(
-                "utest1@i01.v.yattee.stream",
-                fallingBackTo: "utest1@i01.v.yattee.stream"
+                "i01",
+                prefilledWith: "i01",
+                hasUserSetLabel: false
             ) == nil
         )
+        #expect(
+            DataContextValidator.renamedDisplayName(
+                "  utest1@i01.v.yattee.stream  ",
+                prefilledWith: "utest1@i01.v.yattee.stream",
+                hasUserSetLabel: false
+            ) == nil
+        )
+    }
+
+    @Test("Typing a name that happens to match this device's fallback still stores it")
+    func editedNameEqualToTheDefaultIsStored() {
+        // The rule is editedness, not equality with the default. On a second
+        // device the string that device falls back to is an ordinary name to
+        // choose — and the prefill there is the *synced* label, so typing over
+        // it is a real edit that has to store and sync like any other.
+        #expect(
+            DataContextValidator.renamedDisplayName(
+                "i01",
+                prefilledWith: "Main i01",
+                hasUserSetLabel: true
+            ) == "i01"
+        )
+        // Same on an account with no label yet: the prefill was the fallback
+        // "utest1@…", and the user replaced it with something else entirely.
+        #expect(
+            DataContextValidator.renamedDisplayName(
+                "i01",
+                prefilledWith: "utest1@i01.v.yattee.stream",
+                hasUserSetLabel: false
+            ) == "i01"
+        )
+    }
+
+    @Test("Saving a named account untouched keeps its name rather than clearing it")
+    func unchangedNameIsKept() {
+        // Decided semantics for "Save with no edit" on an account that already
+        // carries a label: re-state the label. The manager drops the write as a
+        // no-op, so the name survives and nothing is queued — an idle tap must
+        // never read as "clear the name".
+        #expect(
+            DataContextValidator.renamedDisplayName(
+                "Main i01",
+                prefilledWith: "Main i01",
+                hasUserSetLabel: true
+            ) == "Main i01"
+        )
+    }
+
+    @Test("Both rename surfaces offer the shown label and fall back to the default")
+    func renameRequestIsBuiltFromTheValidator() {
+        let (accounts, instances, validator) = makeFixture()
+        var instance = Instance(type: .invidious, url: URL(string: "https://inv.example.com")!)
+        instance.name = "My Invidious"
+        instances.add(instance)
+
+        let account = accounts.addAccount(instanceID: instance.id)
+
+        let unnamed = AccountRenameRequest.forAccount(account, resolvedBy: validator)
+        #expect(unnamed.id == account.id)
+        #expect(unnamed.defaultName == validator.defaultDisplayName(for: account))
+        #expect(unnamed.initialText == validator.displayName(for: account))
+        #expect(unnamed.hasUserSetLabel == false)
+
+        accounts.updateDisplayName("Main i01", for: account.id)
+        let renamed = accounts.account(id: account.id)!
+
+        let named = AccountRenameRequest.forAccount(renamed, resolvedBy: validator)
+        // The placeholder stays the *default*, never the label being edited:
+        // clearing the field has to advertise where it lands.
+        #expect(named.defaultName == "My Invidious")
+        #expect(named.initialText == "Main i01")
+        #expect(named.hasUserSetLabel)
+    }
+
+    @Test("An orphan's rename request offers only its own label")
+    func orphanRenameRequestSkipsTheValidator() {
+        let (accounts, instances, _) = makeFixture()
+        let instance = Instance(type: .invidious, url: URL(string: "https://inv.example.com")!)
+        instances.add(instance)
+
+        let account = accounts.addAccount(instanceID: instance.id)
+        let unnamed = AccountRenameRequest.forAccount(account, fallingBackTo: "Unnamed")
+        #expect(unnamed.defaultName == "Unnamed")
+        #expect(unnamed.initialText.isEmpty)
+        #expect(unnamed.hasUserSetLabel == false)
+
+        accounts.updateDisplayName("Abandoned login", for: account.id)
+        let named = AccountRenameRequest.forAccount(
+            accounts.account(id: account.id)!,
+            fallingBackTo: "Unnamed"
+        )
+        #expect(named.initialText == "Abandoned login")
+        #expect(named.hasUserSetLabel)
+    }
+
+    @Test("Re-saving the same name writes nothing")
+    func noOpSaveIsNotWritten() {
+        let (accounts, instances, _) = makeFixture()
+        let instance = Instance(type: .invidious, url: URL(string: "https://inv.example.com")!)
+        instances.add(instance)
+
+        let account = accounts.addAccount(instanceID: instance.id)
+
+        // An untouched save on an account with no label: nil over nil.
+        accounts.confirmUpload(account.id)
+        let untouchedAt = accounts.account(id: account.id)?.updatedAt
+        accounts.updateDisplayName(nil, for: account.id)
+        #expect(!accounts.pendingUploads.contains(account.id))
+        #expect(accounts.account(id: account.id)?.updatedAt == untouchedAt)
+
+        accounts.updateDisplayName("Main i01", for: account.id)
+        accounts.confirmUpload(account.id)
+        let renamedAt = accounts.account(id: account.id)?.updatedAt
+
+        // And on one that carries a label: the same string over itself.
+        accounts.updateDisplayName("Main i01", for: account.id)
+        #expect(!accounts.pendingUploads.contains(account.id))
+        #expect(accounts.account(id: account.id)?.updatedAt == renamedAt)
+        #expect(accounts.account(id: account.id)?.displayName == "Main i01")
     }
 
     @Test("The default name ignores the user-set one, and the shown name prefers it")