Fix invalid Context reference.

dbms/src/Formats/ValuesRowInputStream.cpp

 #include <IO/ReadHelpers.h>
 #include <Interpreters/evaluateConstantExpression.h>
+#include <Interpreters/Context.h>
 #include <Interpreters/convertFieldToType.h>
 #include <Parsers/TokenIterator.h>
 #include <Parsers/ExpressionListParsers.h>
@@ -29,8 +30,9 @@ namespace ErrorCodes
 
 
 ValuesRowInputStream::ValuesRowInputStream(ReadBuffer & istr_, const Block & header_, const Context & context_, const FormatSettings & format_settings)
-    : istr(istr_), header(header_), context(context_), format_settings(format_settings)
+    : istr(istr_), header(header_), format_settings(format_settings)
 {
+    context = std::make_unique<Context>(context_);
     /// In this format, BOM at beginning of stream cannot be confused with value, so it is safe to skip it.
     skipBOMIfExists(istr);
 }
@@ -112,7 +114,7 @@ bool ValuesRowInputStream::read(MutableColumns & columns)
 
                 istr.position() = const_cast<char *>(token_iterator->begin);
 
-                std::pair<Field, DataTypePtr> value_raw = evaluateConstantExpression(ast, context);
+                std::pair<Field, DataTypePtr> value_raw = evaluateConstantExpression(ast, *context);
                 Field value = convertFieldToType(value_raw.first, type, value_raw.second.get());
 
                 if (value.isNull())

dbms/src/Formats/ValuesRowInputStream.h

@@ -28,7 +28,7 @@ public:
 private:
     ReadBuffer & istr;
     Block header;
-    const Context & context;
+    std::unique_ptr<Context> context;
     const FormatSettings format_settings;
 };