fix(compose): a resumed draft does not re-seed on a From: change

A resumed draft kept m_signatureChosen false, so a From: change re-seeded
the signature and rewrote what the user had saved, inserting the new
account's where the saved block no longer matched a known file. The draft is
the user's deliberate prior state and must not follow a From: change, so the
draft branch marks it chosen.

2 files changed, 63 insertions, 0 deletions

diff --git a/src/composewindow.cpp b/src/composewindow.cpp
index 94a3f46..d781e52 100644
--- a/src/composewindow.cpp
+++ b/src/composewindow.cpp
@@ -792,6 +792,11 @@ void ComposeWindow::seedSignature()
     // verbatim. Seeding again would append a second one.
     if (m_context.kind == ComposeContext::Kind::Draft) {
         none->setChecked(true);
+        // The draft IS the user's choice: its signature is deliberate prior
+        // state, so a From: change must not follow the new account and
+        // rewrite what was saved. Marking it chosen keeps the same invariant
+        // the switch actions set, without ever having run the switch.
+        m_signatureChosen = true;
         return;
     }
 
diff --git a/tests/test_composewindow.cpp b/tests/test_composewindow.cpp
index 8221ce3..47f7d87 100644
--- a/tests/test_composewindow.cpp
+++ b/tests/test_composewindow.cpp
@@ -46,6 +46,7 @@ private slots:
     void theSwitchListsEveryFileAndNone();
     void changingTheAccountFollowsItsSignature();
     void changingTheAccountStopsFollowingOnceTheSwitchIsUsed();
+    void aResumedDraftDoesNotReseedOnAnAccountChange();
 
 private:
     /// A config pointing at a signatures directory holding \p files, with one
@@ -335,5 +336,62 @@ void TestComposeWindow::changingTheAccountStopsFollowingOnceTheSwitchIsUsed()
     QVERIFY(!body->toPlainText().contains(QStringLiteral("Home sig")));
 }
 
+void TestComposeWindow::aResumedDraftDoesNotReseedOnAnAccountChange()
+{
+    for (const auto &entry :
+         QList<QPair<QString, QString>>{
+             { QStringLiteral("work.md"), QStringLiteral("Work sig") },
+             { QStringLiteral("home.md"), QStringLiteral("Home sig") } }) {
+        QFile file(m_signatureDir + QStringLiteral("/") + entry.first);
+        QVERIFY(file.open(QIODevice::WriteOnly | QIODevice::Text));
+        file.write(entry.second.toUtf8());
+        file.close();
+    }
+
+    const QString path = m_dir->path() + QStringLiteral("/qtmaildir.conf");
+    {
+        QFile file(path);
+        QVERIFY(file.open(QIODevice::WriteOnly | QIODevice::Text));
+        QTextStream out(&file);
+        out << "[account.work]\n"
+            << "name = Someone\naddress = someone@example.org\n"
+            << "maildir = work\nsend_command = /bin/cat\n"
+            << "signature = work\n"
+            << "\n[account.home]\n"
+            << "name = Someone\naddress = other@example.org\n"
+            << "maildir = home\nsend_command = /bin/cat\n"
+            << "signature = home\n";
+    }
+    Config config;
+    config.load(path);
+
+    // The saved body already carries its own signature, which does not match
+    // any on-disk file. A From: change must not replace it with the new
+    // account's: the draft is the message the user wrote, exactly as
+    // seedBody() takes its body verbatim.
+    ComposeContext context;
+    context.kind = ComposeContext::Kind::Draft;
+    context.accountKey = QStringLiteral("work");
+    context.body = QStringLiteral("Half a thought.\n\n-- \nJane Doe");
+    context.draftPath = m_dir->path() + QStringLiteral("/draft");
+
+    ComposeWindow window(context, config, m_dir->path());
+    window.setSignatureDir(m_signatureDir);
+    window.seedSignature();
+
+    auto *body = window.findChild<QPlainTextEdit *>(QStringLiteral("body"));
+    auto *from = window.findChild<QComboBox *>(QStringLiteral("from"));
+    QVERIFY(body);
+    QVERIFY(from);
+    QVERIFY(body->toPlainText().contains(QStringLiteral("Jane Doe")));
+
+    const int home = from->findData(QStringLiteral("home"));
+    QVERIFY(home >= 0);
+    from->setCurrentIndex(home);
+
+    QVERIFY(body->toPlainText().contains(QStringLiteral("Jane Doe")));
+    QVERIFY(!body->toPlainText().contains(QStringLiteral("Home sig")));
+}
+
 QTEST_MAIN(TestComposeWindow)
 #include "test_composewindow.moc"