src/ tests/: avoid exception in Page.annots() to fix #4928.

Looks like self.annot_xrefs() can return bogus xref values, which we now
ignore.

Author: julian-smith-artifex-com

src/__init__.py

@@ -10670,8 +10670,10 @@ def annots(self, types=None):
             annot_xrefs = [a[0] for a in self.annot_xrefs() if a[1] in types and a[1] not in skip_types]
         for xref in annot_xrefs:
             annot = self.load_annot(xref)
-            annot._yielded=True
-            yield annot
+            # In #4928, annot can be None, which we need to ignore.
+            if annot:
+                annot._yielded=True
+                yield annot
 
     def apply_redactions(
             page: 'Page',

tests/test_general.py

@@ -2213,13 +2213,12 @@ def test_4907():
             display_list = page.get_displaylist(annots=False)
             text_page = display_list.get_textpage()
 
+
 def test_4928():
     path = os.path.normpath(f'{__file__}/../../tests/resources/test_4928.pdf')
     with pymupdf.open(path) as document:
-        try:
-            document.scrub()
-        except Exception as e:
-            print(f'Ignoring expected exception: {e}')
+        document.scrub()
+
 
 def test_4902():
     print()