Index: lib/Exchange/JSONExporter.cpp
===================================================================
--- lib/Exchange/JSONExporter.cpp
+++ lib/Exchange/JSONExporter.cpp
@@ -274,9 +274,23 @@

 bool JSONImporter::importContext(Scop &S, Json::Value &JScop) {
   isl_set *OldContext = S.getContext();
+
+  if (!JScop.isMember("context")) {
+    errs() << "JScop file has no key named 'context'.\n";
+    isl_set_free(OldContext);
+    return false;
+  }
+
   isl_set *NewContext =
       isl_set_read_from_str(S.getIslCtx(), JScop["context"].asCString());

+  if (!isl_set_is_params(NewContext)) {
+    errs() << "The isl_set is not a parameter set.\n";
+    isl_set_free(NewContext);
+    isl_set_free(OldContext);
+    return false;
+  }
+
   for (unsigned i = 0; i < isl_set_dim(OldContext, isl_dim_param); i++) {
     isl_id *Id = isl_set_get_dim_id(OldContext, isl_dim_param, i);
     NewContext = isl_set_set_dim_id(NewContext, isl_dim_param, i, Id);