Filled Choice Fields Not Rendered Correctly By Adobe Acrobat

[jacobmiller22]

When reading a form with Adobe Acrobat that previously had a Choice (Drop-down list in Acrobat) field populated with pypdf in the manner specified in the documentation, the default value is always rendered. Behavior does not occur with MacOS Preview.

I did see #2747 , #2611, and #2614, but I wanted to provide a full example for reproducing.

I have also tried this on version 4.3.0 and received the same behavior.

Environment

Which environment were you using when you encountered the problem?

$ python -m platform
macOS-14.5-arm64-arm-64bit

^ Have also experienced this on AWS lambda with amd64 chip and a 2019 MBP with Intel Chip

$ python -c "import pypdf;print(pypdf._debug_versions)"
pypdf==4.2.0, crypt_provider=('local_crypt_fallback', '0.0.0'), PIL=none

Code + PDF

This is a minimal, complete example that shows the issue:

import pypdf

reader = pypdf.PdfReader("./single-dropdown-field.pdf")

writer = pypdf.PdfWriter()
pages = reader.pages[0] # Unused var, Follows the documentation
fields = reader.get_fields() # Unused var, Follows the documentation

writer.append(reader)

print("Fields before update: ", writer.get_fields())
## Formatted for readability
# Fields before update:  
# {
#     'TEST_DROPDOWN': {
#         '/T': 'TEST_DROPDOWN', 
#         '/FT': '/Ch', 
#         '/Ff': 131072, 
#         '/V': 'Unselected', # Value is currently the default value
#         '/DV': 'Unselected', 
#         '/Opt': ['Unselected', 'Item 1', 'Item 2', 'Item 3'], 
#         '/_States_': ['Unselected', 'Item 1', 'Item 2', 'Item 3']
#     }
# }
##

data = {"TEST_DROPDOWN": "Item 2"}

writer.update_page_form_field_values(
    None,
    data,
    auto_regenerate=True, # Same Behavior with both True and False
)

print("Fields after update: ", writer.get_fields())
## Formatted for readability
# Fields after update:  
# {
#     'TEST_DROPDOWN': {
#         '/T': 'TEST_DROPDOWN', 
#         '/FT': '/Ch', 
#         '/Ff': 131072, 
#         '/V': 'Item 2', # Value is correctly assigned my value
#         '/DV': 'Unselected', 
#         '/Opt': ['Unselected', 'Item 1', 'Item 2', 'Item 3'], 
#         '/_States_': ['Unselected', 'Item 1', 'Item 2', 'Item 3']
#     }
# }
##

writer.write("result-single-dropdown-field.pdf")

Share here the PDF file(s) that cause the issue. The smaller they are, the
better. Let us know if we may add them to our tests!

The below PDFs shared may be used in tests if desired. They were created for the sole purpose of creating a simple PDF to reproduce this issue.

single-dropdown-field.pdf

^ Created using Adobe Acrobat, contains a single "Drop-down list" Field with the name TEST_DROPDOWN

result-single-dropdown-field.pdf

^ Result from the script

Snapshots of form in Adobe Acrobat

Posted in comment below

Additional Details

After populating the fields, I can see the /V field is correctly set to the value I want, MacOS preview also renders the PDF correctly. Unfortunately, I need Acrobat compatibility before anything else.

[jacobmiller22]

Snapshots from Adobe Acrobat

Image of PDF before populating. Default value is Unselected

Image of PDF in the Prepare a form menu

[jacobmiller22]

Snapshots from Adobe Acrobat

Images of Fields properties menu:

[stefan6419846]

Have you tried using the latest main code or the 4.3.0 version not yet available on PyPI?

[jacobmiller22]

Hi @stefan6419846

I just downloaded it, I am not facing the same issue with version 4.3.0. When do you think this version will be officially released?

I appreciate everyone's efforts to build this great library!

[stefan6419846]

We intended to get this released already, but our release automation has not been working correctly and thus we are currently waiting for Martin as the maintainer with write permissions to tackle this manually.

[jacobmiller22]

Thank you for the update!