Bug fixes for tests and error handling (#189)

* bugfixes to error handling and tests

- handle potential nullptr coming from strerror(errno)
- removed hardcoded "/tmp" in tests and instead use the TMPDIR variable on Linux and Mac. Depending on the build environment a hard coded "/tmp" may not be accessible, leading to sporadic test failures.

Signed-off-by: The MathWorks, Inc. Roy.Lurie@mathworks.com

* fix spacing

Signed-off-by: The MathWorks, Inc. Roy.Lurie@mathworks.com

* set TMPDIR in tavis ci build

travis ci doesn't appear to automatically set a TMPDIR env var on Linux.


Signed-off-by: The MathWorks, Inc. Roy.Lurie@mathworks.com

* Back out travis CI.

exporting TMPDIR for travis CI linux has issues when running valgrind.

Go back to using a hard-coded "/tmp" during testing only if TMPDIR isn't set.

Signed-off-by: The MathWorks, Inc. Roy.Lurie@mathworks.com

framework/src/util/Utils.cpp

@@ -392,7 +392,8 @@ int GetLastErrorNo()
 std::string GetLastErrorStr()
 {
 #ifdef US_PLATFORM_POSIX
-  return std::string(strerror(errno));
+  char* errorString = strerror(errno);
+  return std::string(((errorString == nullptr)?"":errorString));
 #else
   // Retrieve the system error message for the last-error code
   LPVOID lpMsgBuf;

framework/test/TestUtils.cpp

@@ -163,7 +163,8 @@ std::string GetTempDirectory()
   if (buffer) CoTaskMemFree(static_cast<void*>(buffer));
   return std::string(temp_dir.cbegin(), temp_dir.cend());
 #else
-  return std::string("/tmp");
+  char* tempdir = getenv("TMPDIR");
+  return std::string(((tempdir == nullptr)?"/tmp":tempdir));
 #endif
 }