fix(drafts): index a saved draft so it appears without a sync

Autosave writes the draft to the Maildir drafts folder and stops, while
the Drafts view is a notmuch path: query, so a freshly saved draft was
invisible until notmuch new ran. saveDraftNow() now emits draftSaved, and
MainWindow connects it to a new NotmuchWorker::indexDraftFile() that
indexes the one file the way moveMessages() does, with the previous
revision removed so a rewrite leaves no ghost.

The send path unlinks a draft that was indexed while being composed, so
draftRemoved -> removeIndexedFile() drops its entry too.

Measured: notmuch_database_index_file assigns NO tags (unlike notmuch
new, which adds draft inbox unread), so no tag-stripping is needed and the
draft cannot leak into a tag:inbox view.

Item 158.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/composewindow.cpp b/src/composewindow.cpp
index d781e52..c35bb5d 100644
--- a/src/composewindow.cpp
+++ b/src/composewindow.cpp
@@ -1018,6 +1018,7 @@ bool ComposeWindow::saveDraftNow()
     const QString folder = QDir(m_mailRoot).absoluteFilePath(
         account.maildir + QLatin1Char('/') + account.drafts);
 
+    const QString previousPath = m_draftPath;
     const DraftStore::Result written =
         DraftStore::write(folder, built.bytes, QStringLiteral("D"), m_draftPath);
 
@@ -1038,6 +1039,10 @@ bool ComposeWindow::saveDraftNow()
     m_dirty = false;
     m_saveFailed = false;
     m_banner->hide();
+
+    // The write is done and the previous revision already unlinked; hand both
+    // paths up so the owner indexes the new one and drops the old (item 158).
+    emit draftSaved(written.path, previousPath);
     return true;
 }
 
@@ -1200,6 +1205,7 @@ void ComposeWindow::send()
             dialog->setStage(SendDialog::Stage::RemovingDraft);
             if (!m_draftPath.isEmpty()) {
                 QFile::remove(m_draftPath);
+                emit draftRemoved(m_draftPath);
                 m_draftPath.clear();
             }