Prevent reference XML reader segfault on nullptr error strings

It is possible for TinyXML2 to return null pointers to the error strings.
This could cause XML reference data reader to segfault.

Refs #2241

Change-Id: I8b72917785080023f75388281dd2cbb4f30da925

diff --git a/src/testutils/refdata-xml.cpp b/src/testutils/refdata-xml.cpp
index bdf6018cd81bced5ff944aa8892ec9a59e20e1ae..0b7a8269444dcf20a678865e51196d1cff54fd33 100644 (file)
--- a/src/testutils/refdata-xml.cpp
+++ b/src/testutils/refdata-xml.cpp
@@ -1,7 +1,7 @@
 /*
  * This file is part of the GROMACS molecular simulation package.
  *
- * Copyright (c) 2015,2016, by the GROMACS development team, led by
+ * Copyright (c) 2015,2016,2017, by the GROMACS development team, led by
  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
  * and including many others, as listed in the AUTHORS file in the
  * top-level source directory and at http://www.gromacs.org.
@@ -208,9 +208,21 @@ readReferenceDataFile(const std::string &path)
     document.LoadFile(path.c_str());
     if (document.Error())
     {
+        const char *errorStr1 = document.GetErrorStr1();
+        const char *errorStr2 = document.GetErrorStr2();
         std::string errorString("Error was ");
-        errorString += document.GetErrorStr1();
-        errorString += document.GetErrorStr2();
+        if (errorStr1)
+        {
+            errorString += errorStr1;
+        }
+        if (errorStr2)
+        {
+            errorString += errorStr2;
+        }
+        if (!errorStr1 && !errorStr2)
+        {
+            errorString += "not specified.";
+        }
         GMX_THROW(TestException("Reference data not parsed successfully: " + path + "\n." + errorString + "\n"));
     }
     XMLElementPtr rootNode = document.RootElement();