UPBGE: Fix crash when calling Texture_init with material without text…

…ure.

Previously if the texture index was pointing to an invalid RAS_Texture
a memory exeption was raised, because the Texture class in function
Texture_init was not checking if the RAS_Texture was valid before acces
to its datas.

To solve this a check is made and a new exeption TextureNotAvail is raised.
This exeption print the error message:
Texture is not available.

source/gameengine/VideoTexture/Exception.cpp

@@ -209,6 +209,7 @@ void registerAllExceptions(void)
 {
 	errGenerDesc.registerDesc();
 	errNFoundDesc.registerDesc();
+	TextureNotAvailDesc.registerDesc();
 	MaterialNotAvailDesc.registerDesc();
 	ImageSizesNotMatchDesc.registerDesc();
 	ImageHasExportsDesc.registerDesc();

source/gameengine/VideoTexture/Exception.h

@@ -206,6 +206,7 @@ class Exception : public std::exception
 };
 
 extern ExpDesc MaterialNotAvailDesc;
+extern ExpDesc TextureNotAvailDesc;
 extern ExpDesc ImageSizesNotMatchDesc;
 extern ExpDesc ImageHasExportsDesc;
 extern ExpDesc InvalidColorChannelDesc;

source/gameengine/VideoTexture/Texture.cpp

@@ -209,6 +209,9 @@ static void Texture_dealloc(Texture *self)
 ExceptionID MaterialNotAvail;
 ExpDesc MaterialNotAvailDesc(MaterialNotAvail, "Texture material is not available");
 
+ExceptionID TextureNotAvail;
+ExpDesc TextureNotAvailDesc(TextureNotAvail, "Texture is not available");
+
 // Texture object initialization
 static int Texture_init(Texture *self, PyObject *args, PyObject *kwds)
 {
@@ -242,6 +245,9 @@ static int Texture_init(Texture *self, PyObject *args, PyObject *kwds)
 			{
 				// get blender material texture
 				self->m_matTexture = mat->GetTexture(texID);
+				if (!self->m_matTexture) {
+					THRWEXCP(TextureNotAvail, S_OK);
+				}
 				self->m_imgTexture = self->m_matTexture->GetImage();
 				self->m_useMatTexture = true;
 			}

source/gameengine/VideoTexture/Texture.h

@@ -97,5 +97,6 @@ short getMaterialID(PyObject *obj, const char *name);
 
 // Exceptions
 extern ExceptionID MaterialNotAvail;
+extern ExceptionID TextureNotAvail;
 
 #endif