Update logic to allow split default when path set (#1782)

* Update logic to allow split default when path set

* Fix default split-image-groups case

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Co-authored-by: Piero Toffanin <pt@masseranolabs.com>

stages/splitmerge.py

@@ -29,14 +29,15 @@ def process(self, args, outputs):
         photos = reconstruction.photos
         outputs['large'] = False
 
-        should_split = len(photos) > args.split
-
-        if should_split:
-            # check for availability of either image_groups.txt (split-merge) or geotagged photos
-            image_groups_file = os.path.join(args.project_path, "image_groups.txt")
-            if 'split_image_groups_is_set' in args:
-                image_groups_file = os.path.abspath(args.split_image_groups)
-            if io.file_exists(image_groups_file) or reconstruction.has_geotagged_photos():
+        image_groups_file = os.path.join(args.project_path, "image_groups.txt")
+        if 'split_image_groups_is_set' in args:
+            image_groups_file = os.path.abspath(args.split_image_groups)
+
+        if io.file_exists(image_groups_file):
+            outputs['large'] = True
+        elif len(photos) > args.split:
+            # check for availability of geotagged photos
+            if reconstruction.has_geotagged_photos():
                 outputs['large'] = True
             else:
                 log.ODM_WARNING('Could not perform split-merge as GPS information in photos or image_groups.txt is missing.')