More fixes related to D&D:

* Same issue as T42760 was also reproducible in some cases in 3DView.
* You got an error message about missing RNA prop in some drop-called operators.
* You could not drop a movie file in nodes, (some cases of) 3DView, nor ImageEditor.

source/blender/editors/space_node/node_add.c

@@ -374,7 +374,7 @@ void NODE_OT_add_file(wmOperatorType *ot)
 	/* flags */
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 
-	WM_operator_properties_filesel(ot, FOLDERFILE | IMAGEFILE, FILE_SPECIAL, FILE_OPENFILE,
+	WM_operator_properties_filesel(ot, FOLDERFILE | IMAGEFILE | MOVIEFILE, FILE_SPECIAL, FILE_OPENFILE,
 	                               WM_FILESEL_FILEPATH | WM_FILESEL_RELPATH, FILE_DEFAULTDISPLAY);
 	RNA_def_string(ot->srna, "name", "Image", MAX_ID_NAME - 2, "Name", "Datablock name to assign");
 }