@@ -96,9 +96,6 @@ public static void GetProgramNameDefault()
         /// Test default behavior of PYTHONHOME. If ENVVAR is set it will
         /// return the same value. If not, returns EmptyString.
         /// </summary>
-        /// <remarks>
-        /// AppVeyor.yml has been update to tests with ENVVAR set.
-        /// </remarks>
         [Test]
         public static void GetPythonHomeDefault()
         {
@@ -114,22 +111,19 @@ public static void GetPythonHomeDefault()
         [Test]
         public void SetPythonHome()
         {
-            // We needs to ensure that engine was started and shutdown at least once before setting dummy home.
-            // Otherwise engine will not run with dummy path with random problem.
-            if (!PythonEngine.IsInitialized)
-            {
-                PythonEngine.Initialize();
-            }
-
+            PythonEngine.Initialize();
+            var pythonHomeBackup = PythonEngine.PythonHome;
             PythonEngine.Shutdown();
 
-            var pythonHomeBackup = PythonEngine.PythonHome;
+            if (pythonHomeBackup == "")
+                Assert.Inconclusive("Can't reset PythonHome to empty string, skipping");
 
             var pythonHome = "/dummypath/";
 
             PythonEngine.PythonHome = pythonHome;
             PythonEngine.Initialize();
 
+            Assert.AreEqual(pythonHome, PythonEngine.PythonHome);
             PythonEngine.Shutdown();
 
             // Restoring valid pythonhome.
@@ -139,15 +133,12 @@ public void SetPythonHome()
         [Test]
         public void SetPythonHomeTwice()
         {
-            // We needs to ensure that engine was started and shutdown at least once before setting dummy home.
-            // Otherwise engine will not run with dummy path with random problem.
-            if (!PythonEngine.IsInitialized)
-            {
-                PythonEngine.Initialize();
-            }
+            PythonEngine.Initialize();
+            var pythonHomeBackup = PythonEngine.PythonHome;
             PythonEngine.Shutdown();
 
-            var pythonHomeBackup = PythonEngine.PythonHome;
+            if (pythonHomeBackup == "")
+                Assert.Inconclusive("Can't reset PythonHome to empty string, skipping");
 
             var pythonHome = "/dummypath/";
 
@@ -161,6 +152,26 @@ public void SetPythonHomeTwice()
             PythonEngine.PythonHome = pythonHomeBackup;
         }
 
+        [Test]
+        [Ignore("Currently buggy in Python")]
+        public void SetPythonHomeEmptyString()
+        {
+            PythonEngine.Initialize();
+
+            var backup = PythonEngine.PythonHome;
+            if (backup == "")
+            {
+                PythonEngine.Shutdown();
+                Assert.Inconclusive("Can't reset PythonHome to empty string, skipping");
+            }
+            PythonEngine.PythonHome = "";
+
+            Assert.AreEqual("", PythonEngine.PythonHome);
+
+            PythonEngine.PythonHome = backup;
+            PythonEngine.Shutdown();
+        }
+
         [Test]
         public void SetProgramName()
         {
@@ -207,7 +218,7 @@ public void SetPythonPath()
             // The list sys.path is initialized with this value on interpreter startup;
             // it can be (and usually is) modified later to change the search path for loading modules.
             // See https://docs.python.org/3/c-api/init.html#c.Py_GetPath
-            // After PythonPath is set, then PythonEngine.PythonPath will correctly return the full search path. 
+            // After PythonPath is set, then PythonEngine.PythonPath will correctly return the full search path.
 
             PythonEngine.Shutdown();
 
 
@@ -47,6 +47,14 @@ public static bool IsInitialized
             get { return initialized; }
         }
 
+        private static void EnsureInitialized()
+        {
+            if (!IsInitialized)
+                throw new InvalidOperationException(
+                    "Python must be initialized for this operation"
+                );
+        }
+
         /// <summary>Set to <c>true</c> to enable GIL debugging assistance.</summary>
         public static bool DebugGIL { get; set; } = false;
 
@@ -96,17 +104,16 @@ public static string PythonHome
         {
             get
             {
+                EnsureInitialized();
                 IntPtr p = Runtime.TryUsingDll(() => Runtime.Py_GetPythonHome());
                 return UcsMarshaler.PtrToPy3UnicodePy2String(p) ?? "";
             }
             set
             {
                 // this value is null in the beginning
                 Marshal.FreeHGlobal(_pythonHome);
-                _pythonHome = Runtime.TryUsingDll(
-                    () => UcsMarshaler.Py3UnicodePy2StringtoPtr(value)
-                );
-                Runtime.Py_SetPythonHome(_pythonHome);
+                _pythonHome = UcsMarshaler.Py3UnicodePy2StringtoPtr(value);
+                Runtime.TryUsingDll(() => Runtime.Py_SetPythonHome(_pythonHome));
             }
         }
Original file line number	Diff line number	Diff line change
@@ -47,6 +47,14 @@ public static bool IsInitialized
47	47	get { return initialized; }
48	48	}
49	49
	50	+ private static void EnsureInitialized()
	51	+ {
	52	+ if (!IsInitialized)
	53	+ throw new InvalidOperationException(
	54	+ "Python must be initialized for this operation"
	55	+ );
	56	+ }
	57	+
50	58	/// <summary>Set to <c>true</c> to enable GIL debugging assistance.</summary>
51	59	public static bool DebugGIL { get; set; } = false;
52	60
@@ -96,17 +104,16 @@ public static string PythonHome
96	104	{
97	105	get
98	106	{
	107	+ EnsureInitialized();
99	108	IntPtr p = Runtime.TryUsingDll(() => Runtime.Py_GetPythonHome());
100	109	return UcsMarshaler.PtrToPy3UnicodePy2String(p) ?? "";
101	110	}
102	111	set
103	112	{
104	113	// this value is null in the beginning
105	114	Marshal.FreeHGlobal(_pythonHome);
106		- _pythonHome = Runtime.TryUsingDll(
107		- () => UcsMarshaler.Py3UnicodePy2StringtoPtr(value)
108		- );
109		- Runtime.Py_SetPythonHome(_pythonHome);
	115	+ _pythonHome = UcsMarshaler.Py3UnicodePy2StringtoPtr(value);
	116	+ Runtime.TryUsingDll(() => Runtime.Py_SetPythonHome(_pythonHome));
110	117	}
111	118	}
112	119