Add test for empty char list

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "marker-pdf"
-version = "1.7.2"
+version = "1.7.3"
 description = "Convert documents to markdown with high speed and accuracy."
 authors = ["Vik Paruchuri <github@vikas.sh>"]
 readme = "README.md"

tests/builders/test_ocr_builder.py

@@ -0,0 +1,10 @@
+from PIL import Image
+
+from marker.builders.ocr import OcrBuilder
+
+
+def test_blank_char_builder(recognition_model):
+    builder = OcrBuilder(recognition_model)
+    image = Image.new("RGB", (100, 100))
+    spans = builder.spans_from_html_chars([], None, image)  # Test with empty char list
+    assert len(spans) == 0