fix(startup): raise the config-problem modal outside the constructor

showWarnings() did two separable things and one of them could not be
reached from a test. It set the status label, which is harmless, and it
raised a QMessageBox from the MainWindow constructor, which under the
offscreen platform nothing can dismiss: the constructor never returned
and the suite hung with no output, reading as an infrastructure failure
rather than a test one.

It splits in two. applyWarnings() keeps the status label and stays in
the constructor. configProblems() returns the list, and main.cpp raises
the dialog after show(), which also gives it a visible parent to sit on.

The distinction between warnings and problems is preserved exactly: a
keybinding being ignored interrupts startup, "no sync command
configured" does not.

The warning path now has its first test, using the config shape that
caused the original hang. Mutation checked by putting the modal back in
the constructor: the test times out at 124 rather than failing, which is
the behaviour this removes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/tests/test_mainwindow.cpp b/tests/test_mainwindow.cpp
index 0bf8925..be3a28f 100644
--- a/tests/test_mainwindow.cpp
+++ b/tests/test_mainwindow.cpp
@@ -91,6 +91,7 @@ private slots:
     void aSearchFromThePaneReplacesTheQuery();
     void aSearchFromThePaneCanNarrowTheQuery();
     void narrowingAnEmptyQueryBarIsAPlainSearch();
+    void aMalformedAccountIsReportedWithoutBlockingTheConstructor();
     void autoSyncIsNotArmedWhenDisabledOrWithNothingPending();
     void autoSyncSkipsWhileABackgroundSyncIsRunning();
     void aSuccessfulSyncRefreshesRatherThanRerunningTheQuery();
@@ -6105,4 +6106,38 @@ void TestMainWindow::renamingReplacesRatherThanDuplicating()
     QCOMPARE(savedQueryButtonLabels(window), QStringList{ QStringLiteral("New") });
 }
 
+void TestMainWindow::aMalformedAccountIsReportedWithoutBlockingTheConstructor()
+{
+    // The exact shape that hung the suite on 2026-08-14: an account section
+    // carrying `sent=` and no `maildir=`. Config::load handles it correctly,
+    // recording a problem and carrying on, but showWarnings() then raised a
+    // modal FROM THE CONSTRUCTOR, which nothing can dismiss under the
+    // offscreen platform, so MainWindow never finished constructing.
+    //
+    // Constructing the window at all is therefore half the assertion: if the
+    // modal comes back, this test does not fail, it HANGS.
+    QTemporaryDir dir;
+    QVERIFY(dir.isValid());
+
+    const QString path = dir.filePath(QStringLiteral("qtmaildir.conf"));
+    {
+        QFile file(path);
+        QVERIFY(file.open(QIODevice::WriteOnly | QIODevice::Text));
+        QTextStream out(&file);
+        out << "[account.one]\n"
+            << "sent=Sent\n";
+    }
+
+    Config config;
+    config.load(path);
+
+    MainWindow window(config);
+
+    // The problem is reported rather than swallowed, and it names the account.
+    const QStringList problems = window.configProblems();
+    QVERIFY2(!problems.isEmpty(),
+             "a malformed account produced no problem to report");
+    QVERIFY(problems.join(QLatin1Char('\n')).contains(QStringLiteral("one")));
+}
+
 #include "test_mainwindow.moc"