Adding unit test coverage of search_env_path.

radixcore/tests/tstSystem.cc

@@ -205,3 +205,19 @@ TEST(GetPaths, Basic)
     EXPECT_EQ("a", paths[0]);
   }
 }
+
+TEST(System, SearchEnvPath)
+{
+  std::string app;
+  std::string blessed;
+
+#ifdef _WIN32
+  app     = "where.exe";
+  blessed = "c:\\Windows\\System32\\where.exe";
+#else
+  app     = "ls";
+  blessed = "/usr/bin/ls";
+#endif
+  std::string path = search_env_path(app);
+  EXPECT_EQ(blessed, path);
+}