QmlJS: Fix potential crash in find usages.

When invalid documents or documents without idEnvironment or rootScope
get added to a QmlComponentChain.

Change-Id: I64b7062881f19777ba20efda6efa2e7bab02571e
Reviewed-by: Leandro Melo <leandro.melo@nokia.com>
(cherry picked from commit 9b411ed5588db9dcbea955e4e45f99b5d06c1cbe)
Reviewed-by: Eike Ziller <eike.ziller@nokia.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/src/plugins/qmljseditor/qmljsfindreferences.cpp b/src/plugins/qmljseditor/qmljsfindreferences.cpp
index 49b18e499d..1dddc575de 100644
--- a/src/plugins/qmljseditor/qmljsfindreferences.cpp
+++ b/src/plugins/qmljseditor/qmljsfindreferences.cpp
@@ -246,13 +246,14 @@ protected:
 private:
     bool contains(const QmlComponentChain *chain)
     {
-        if (!chain || !chain->document())
+        if (!chain || !chain->document() || !chain->document()->bind())
             return false;
 
-        if (chain->document()->bind()->idEnvironment()->lookupMember(_name, _scopeChain.context()))
-            return chain->document()->bind()->idEnvironment() == _scope;
+        const ObjectValue *idEnv = chain->document()->bind()->idEnvironment();
+        if (idEnv && idEnv->lookupMember(_name, _scopeChain.context()))
+            return idEnv == _scope;
         const ObjectValue *root = chain->document()->bind()->rootObjectValue();
-        if (root->lookupMember(_name, _scopeChain.context())) {
+        if (root && root->lookupMember(_name, _scopeChain.context())) {
             return check(root);
         }