fix issue reported in '[#33876] bpy.path.ensure_ext adds extension twice / extra period if filename empty, just a period or equal to extension'

For python operators that used the ExportHelper mix-in class, an empty file field would become '.ext', entering and existing the text field would become '.ext.ext',
Now only add an extension if the filename part of the path is set, so '.ext' will still become '.ext.ext' but having only the extension isn't so likely to happen in the first place now.

This is a different fix then the changes suggested in the report but I'd prefer to keep path functions stupid+predictable.

1 files changed, 11 insertions, 8 deletions

diff --git a/release/scripts/modules/bpy_extras/io_utils.py b/release/scripts/modules/bpy_extras/io_utils.py
index 4457ecb43e6..0e9b6c136e9 100644
--- a/release/scripts/modules/bpy_extras/io_utils.py
+++ b/release/scripts/modules/bpy_extras/io_utils.py
@@ -79,20 +79,23 @@ class ExportHelper:
         return {'RUNNING_MODAL'}
 
     def check(self, context):
+        import os
         change_ext = False
         change_axis = _check_axis_conversion(self)
 
         check_extension = self.check_extension
 
         if check_extension is not None:
-            filepath = bpy.path.ensure_ext(self.filepath,
-                                           self.filename_ext
-                                           if check_extension
-                                           else "")
-
-            if filepath != self.filepath:
-                self.filepath = filepath
-                change_ext = True
+            filepath = self.filepath
+            if os.path.basename(filepath):
+                filepath = bpy.path.ensure_ext(filepath,
+                                               self.filename_ext
+                                               if check_extension
+                                               else "")
+
+                if filepath != self.filepath:
+                    self.filepath = filepath
+                    change_ext = True
 
         return (change_ext or change_axis)