Check if the document ptr is not null

Avoid a crash when double click in hierarchy view
after the session has been changed or when the filename
changed.

Change-Id: Iebd7a99c220737262c79ade43c4ee8d11dcc037f
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/plugins/cpptools/cppelementevaluator.cpp b/src/plugins/cpptools/cppelementevaluator.cpp
index 5cfdddcf2c..9cb6c6f807 100644
--- a/src/plugins/cpptools/cppelementevaluator.cpp
+++ b/src/plugins/cpptools/cppelementevaluator.cpp
@@ -548,6 +548,9 @@ public:
                     QString &expression)
     {
         doc = snapshot.document(m_fileName);
+        if (doc.isNull())
+            return false;
+
         expression = m_expression;
 
         // Fetch the expression's code
@@ -729,6 +732,8 @@ Utils::Link CppElementEvaluator::linkFromExpression(const QString &expression, c
 {
     const Snapshot &snapshot = CppModelManager::instance()->snapshot();
     Document::Ptr doc = snapshot.document(fileName);
+    if (doc.isNull())
+        return Utils::Link();
     Scope *scope = doc->globalNamespace();
 
     TypeOfExpression typeOfExpression;