feat(completion): render the popup with descriptions

The free-form date hint is a footer label rather than a model row: a row
would be filtered away by the first non-matching keystroke and could be
selected and inserted, producing a query that errors.

QCompleter::setPopup takes a QAbstractItemView, so the label cannot be laid
out beside the view in a container widget. The footer sits in space reserved
with setViewportMargins inside the list view instead.

setItemDelegate must run after setPopup, not before: setPopup installs a
plain QStyledItemDelegate of its own and discards whatever was already set,
which silently drops the description column.

Accepting replaces exactly the span the tokenizer identified rather than
QCompleter's own completion prefix, which is a different span once a prefix
or a range bound is involved. Four tests drive that path directly instead of
through synthetic key events, since whether a key needs Shift is a
keyboard-layout property and could not decide the question.

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

1 files changed, 55 insertions, 0 deletions

diff --git a/tests/test_querycompleter.cpp b/tests/test_querycompleter.cpp
index bd1e50f..56b5343 100644
--- a/tests/test_querycompleter.cpp
+++ b/tests/test_querycompleter.cpp
@@ -19,6 +19,8 @@
 #include <QtTest>
 #include <QTemporaryDir>
 
+#include <QLineEdit>
+
 #include "config.h"
 #include "querycompleter.h"
 
@@ -48,6 +50,10 @@ private slots:
     void folderOffersNothing();
     void mimetypeAppendsConfiguredEntries();
     void rangeContextDropsRelativeDates();
+    void acceptReplacesOnlyThePrefixToken();
+    void acceptReplacesOnlyTheValueAfterThePrefix();
+    void acceptReplacesOnlyTheEditedRangeBound();
+    void acceptReplacesTheWholeBoundWhenCompletingMidWord();
 };
 
 // Copied from tests/test_config.cpp rather than shared, so the two test files
@@ -298,5 +304,54 @@ void TestQueryCompleter::rangeContextDropsRelativeDates()
     QVERIFY(!inRange.contains(QStringLiteral("1week..")));
 }
 
+// The accept path is driven directly rather than through synthetic key
+// events: whether a key needs Shift is a keyboard-layout property, so
+// QTest::keyClick could never decide whether this logic is right.
+static QString acceptInto(const QString &text, int cursor, const QString &value)
+{
+    Config config;
+    QLineEdit edit;
+    QueryCompleter completer(&edit, config);
+
+    edit.setText(text);
+    edit.setCursorPosition(cursor);
+    completer.updateContext();
+    completer.acceptCompletion(value);
+
+    return edit.text();
+}
+
+void TestQueryCompleter::acceptReplacesOnlyThePrefixToken()
+{
+    // The neighbouring token must survive untouched.
+    QCOMPARE(acceptInto(QStringLiteral("tag:inbox su"), 12,
+                        QStringLiteral("subject:")),
+             QStringLiteral("tag:inbox subject:"));
+}
+
+void TestQueryCompleter::acceptReplacesOnlyTheValueAfterThePrefix()
+{
+    // QCompleter's own insertion would overwrite "date:tod" whole, because
+    // that is the token it matched on. Only "tod" may be replaced.
+    QCOMPARE(acceptInto(QStringLiteral("date:tod"), 8, QStringLiteral("today")),
+             QStringLiteral("date:today"));
+}
+
+void TestQueryCompleter::acceptReplacesOnlyTheEditedRangeBound()
+{
+    const QString text = QStringLiteral("date:yesterday..to");
+    QCOMPARE(acceptInto(text, text.size(), QStringLiteral("today")),
+             QStringLiteral("date:yesterday..today"));
+}
+
+void TestQueryCompleter::acceptReplacesTheWholeBoundWhenCompletingMidWord()
+{
+    // Caret sits after "yest" but the bound runs to the "..", so accepting
+    // must leave no "erday" tail behind.
+    QCOMPARE(acceptInto(QStringLiteral("date:yesterday..today"), 9,
+                        QStringLiteral("this_week")),
+             QStringLiteral("date:this_week..today"));
+}
+
 QTEST_MAIN(TestQueryCompleter)
 #include "test_querycompleter.moc"