Fix Error 500 on multimodal input with empty base64 image data

[Copilot]

QQ platform occasionally sends image messages with file: "base64://" containing no actual base64 data. The bot would decode this empty string, create a 0-byte file, re-encode it as empty base64, and send data:image/jpeg;base64, to the LLM API, causing Error 500: "base64 string is empty".

Changes

Validation at decode points

• Image.convert_to_file_path() and convert_to_base64(): Raise ValueError if base64 data is empty after prefix removal
• Record: Same validation for consistency
• openai_source.encode_image_bs64(): Return empty string with warning for empty base64

Error handling

• llm_request.py: Catch ValueError from convert_to_file_path(), log warning, skip invalid images
• LLM requests continue with remaining valid content

Example flow

# Before: Creates empty file, sends malformed data to API
image = Image(file="base64://")
await image.convert_to_file_path()  # Returns path to 0-byte file → Error 500

# After: Fails fast with clear error
await image.convert_to_file_path()  # ValueError: Base64 data is empty for image: base64://
# Handler logs: "跳过无效图片: Base64 data is empty..." and continues

Fixes #3239

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• api.soulter.top
  • Triggering command: /home/REDACTED/work/AstrBot/AstrBot/.venv/bin/python /home/REDACTED/work/AstrBot/AstrBot/.venv/bin/pytest tests/ -v (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

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Original prompt

#3239
修复这个issue

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[Copilot]

Pull Request Overview

This PR adds validation to prevent empty base64 data from causing issues in image processing. When base64:// prefixes are removed but leave empty strings, the code now properly detects and handles these cases.

Key changes:

• Added empty base64 data validation checks across image and record handling methods
• Added error handling in LLM request processing to gracefully skip invalid images
• Enhanced error messages to include context about which image/record failed

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
astrbot/core/message/components.py	Added empty base64 validation checks in Record and Image classes' convert_to_file_path() and convert_to_base64() methods
astrbot/core/pipeline/process_stage/method/llm_request.py	Wrapped image path conversion in try-except to gracefully handle ValueError from invalid images
astrbot/core/provider/sources/openai_source.py	Added empty base64 validation in encode_image_bs64() method with warning log and early return

[Copilot]

The file_to_base64() function always returns strings prefixed with "base64://", so after removing the prefix on line 482, bs64_data can never be empty (it will always contain the base64-encoded content). This validation check is unreachable and will never trigger. The validation should occur before calling file_to_base64() or should validate the actual data content length.

[Copilot]

Pull Request Overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

[Copilot]

Pull Request Overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.