Make SetExpression check whether the LHS is null

fixes #7814

diff --git a/lib/config/expression.cpp b/lib/config/expression.cpp
index da9e32f1f7ba4bbfd1ab2e29619726c444bc27a2..895e00026cb22ecd2b73b5521f6592695711820a 100644 (file)
--- a/lib/config/expression.cpp
+++ b/lib/config/expression.cpp
@@ -280,6 +280,10 @@ Value SetExpression::DoEvaluate(VMFrame& frame, DebugHint *dhint) const
 
                        if (!vexpr) {
                                object = indexExpr->Evaluate(frame, dhint);
+
+                               if (!object)
+                                       BOOST_THROW_EXCEPTION(ConfigError("Left-hand side argument must not be null."));
+
                                continue;
                        }