14.29: the blank start tab stays put; Untitled numbers stay low

src/Document/ProjectWorkspace.cpp

@@ -3,6 +3,7 @@
 #include "Logging.h"
 #include <QFileDialog>
 #include <QFileInfo>
+#include <QSet>
 #include <QTimer>
 #include <algorithm>
 
@@ -72,12 +73,30 @@ void ProjectWorkspace::finish(const std::function<void(bool)> &done, bool value)
         QMetaObject::invokeMethod(this, [done, value] { done(value); }, Qt::QueuedConnection);
 }
 
+// "Untitled", else the lowest "Untitled N" no tab shows.
+QString ProjectWorkspace::freeUntitledName() const
+{
+    QSet<QString> taken;
+    for (const std::shared_ptr<ProjectTab> &each : m_tabs)
+        taken.insert(each->title());
+    if (!taken.contains(QStringLiteral("Untitled")))
+        return QStringLiteral("Untitled");
+    int number = 2;
+    while (taken.contains(QStringLiteral("Untitled %1").arg(number)))
+        number += 1;
+    return QStringLiteral("Untitled %1").arg(number);
+}
+
+bool ProjectWorkspace::canClose(const ProjectTab &tab) const
+{
+    return !(m_tabs.size() == 1 && !tab.session.document() && !tab.session.projectPath());
+}
+
 ProjectTab &ProjectWorkspace::addTab(bool reuseEmpty)
 {
     if (reuseEmpty && m_tabs.size() == 1 && !current().session.document())
         return current();
-    const auto added = std::make_shared<ProjectTab>(QStringLiteral("Untitled %1").arg(m_nextNumber));
-    m_nextNumber += 1;
+    const auto added = std::make_shared<ProjectTab>(freeUntitledName());
     added->controller.workspace = this;
     added->controller.window = window;
     m_tabs.push_back(added);
@@ -182,7 +201,7 @@ void ProjectWorkspace::loadProject(const QString &path, std::function<void(bool)
 void ProjectWorkspace::close(QUuid id, std::function<void()> done)
 {
     const std::shared_ptr<ProjectTab> closing = tab(id);
-    if (!canSwitch() || !closing) {
+    if (!canSwitch() || !closing || !canClose(*closing)) {
         finish(done);
         return;
     }

src/Document/ProjectWorkspace.h

@@ -34,6 +34,8 @@ public:
     ProjectTab &current() const;
     std::shared_ptr<ProjectTab> tab(QUuid id) const;
     bool canSwitch() const;
+    // The only tab, still blank, has nothing to close.
+    bool canClose(const ProjectTab &tab) const;
     ProjectTab &addTab(bool reuseEmpty = true);
     void select(QUuid id);
     // A dragged tab lands at `index`, clamped; chrome, never undone.
@@ -74,6 +76,7 @@ signals:
     void changed();
 
 private:
+    QString freeUntitledName() const;
     bool finishTextEditing();
     struct Baked {
         EditorSession::BakedImages images;
@@ -102,5 +105,4 @@ private:
     std::vector<std::shared_ptr<ProjectTab>> m_tabs;
     QUuid m_selectedID;
     bool m_isManaging = false;
-    int m_nextNumber = 2;
 };

src/UI/ProjectTabs.cpp

@@ -86,8 +86,11 @@ void ProjectTabButton::synchronize()
     const QFontMetrics metrics(tabFont(active));
     m_select->setText(dot + metrics.elidedText(tab->title(), Qt::ElideRight, label - (modified ? 10 : 0)));
     m_select->setFont(tabFont(active));
-    // Swift's trailing 8 inside; a character dot outgrows Swift's 10.
-    m_select->setFixedWidth(label + 8 + (modified ? metrics.horizontalAdvance(dot) - 10 : 0));
+    // Trailing 8, or 11 closed up; a dot outgrows 10.
+    const bool closable = m_workspace.canClose(*tab);
+    m_select->setFixedWidth(label + (closable ? 8 : 11) + (modified ? metrics.horizontalAdvance(dot) - 10 : 0));
+    layout()->setContentsMargins(11, 0, closable ? 5 : 0, 0);
+    m_close->setVisible(closable);
     m_select->setToolTip(tab->title());
     m_select->setEnabled(m_workspace.canSwitch() || active);
     m_close->setToolTip(QStringLiteral("Close %1").arg(tab->title()));