Intercept erroneous widgets

When copying widgets as part of insert_pdf() processing, badly defined source widgets cause MuPDF exceptions when building their grafted object version.
This fix intercepts MuPDF exceptions and ignores such widgets.

Author: JorjMcKie

src/utils.py

@@ -1987,7 +1987,11 @@ def get_acroform(doc):
                 w_obj.pdf_dict_get(pymupdf.PDF_NAME("Parent"))
             )
             if parent_xref == 0:  # parent not in target yet
-                w_obj_graft = mupdf.pdf_graft_mapped_object(graftmap, w_obj)
+                try:
+                    w_obj_graft = mupdf.pdf_graft_mapped_object(graftmap, w_obj)
+                except Exception as e:
+                    pymupdf.message_warning(f"cannot copy widget at {xref=}: {e}")
+                    continue
                 w_obj_tar = mupdf.pdf_add_object(tarpdf, w_obj_graft)
                 tar_xref = w_obj_tar.pdf_to_num()
                 w_obj_tar_ind = mupdf.pdf_new_indirect(tarpdf, tar_xref, 0)

tests/resources/test_4614.pdf

@@ -0,0 +1,10 @@
+import pymupdf
+import os
+
+
+def test_4614():
+    script_dir = os.path.dirname(__file__)
+    filename = os.path.join(script_dir, "resources", "test_4614.pdf")
+    src = pymupdf.open(filename)
+    doc = pymupdf.open()
+    doc.insert_pdf(src)