Don't crash on invalid nested state machines

If an <invoke> tag doesn't contain a state machine, that's an error
and should be found when verifying. Also, don't try to verify the
nonexistent state machine.

Change-Id: Ib371f3f34c9ab5c20f9492b326d1fee87f7b76d2
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/scxml/qscxmlparser.cpp b/src/scxml/qscxmlparser.cpp
index a0f247b..431077c 100644
--- a/src/scxml/qscxmlparser.cpp
+++ b/src/scxml/qscxmlparser.cpp
@@ -287,8 +287,12 @@ private:
 
     bool visit(DocumentModel::Invoke *node) Q_DECL_OVERRIDE
     {
-        ScxmlVerifier subVerifier(m_errorHandler);
-        m_hasErrors = !subVerifier.verify(node->content.data());
+        if (node->content.isNull()) {
+            error(node->xmlLocation, QStringLiteral("no valid content found in <invoke> tag"));
+        } else {
+            ScxmlVerifier subVerifier(m_errorHandler);
+            m_hasErrors = !subVerifier.verify(node->content.data());
+        }
         return false;
     }