Editor: fix crashing on updating snippet selections

The final selection is not tracked in m_selections and needs to be
handled explicitly. Also add an assert preventing unconditionally
accessing an out of bounds element of m_selections.

Fixes: QTCREATORBUG-28631
Change-Id: I1898418b1126bdaffccbdf0e483e2c659d191917
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/plugins/texteditor/snippets/snippetoverlay.cpp b/src/plugins/texteditor/snippets/snippetoverlay.cpp
index 6824c0470a..f7b3cf80c9 100644
--- a/src/plugins/texteditor/snippets/snippetoverlay.cpp
+++ b/src/plugins/texteditor/snippets/snippetoverlay.cpp
@@ -38,8 +38,13 @@ void SnippetOverlay::setFinalSelection(const QTextCursor &cursor, const QColor &
 void SnippetOverlay::updateEquivalentSelections(const QTextCursor &cursor)
 {
     const int &currentIndex = indexForCursor(cursor);
+    if (currentIndex == m_finalSelectionIndex) {
+        accept();
+        return;
+    }
     if (currentIndex < 0)
         return;
+    QTC_ASSERT(currentIndex < m_selections.size(), return);
     const QString &currentText = cursorForIndex(currentIndex).selectedText();
     const QList<int> &equivalents = m_variables.value(m_selections[currentIndex].variableIndex);
     for (int i : equivalents) {