Description

The ai-prompt-decorator plugin accumulated user messages across multiple requests due to a Lua table reference issue.

Root Cause:

  local new_messages = conf.prepend or EMPTY  -- Direct reference, not copy
  This caused new_messages to point to the same table as conf.prepend, so modifications accumulated in the original configuration.

Solution:

  local messages = {}
  if conf.prepend then
      for i = 1, #conf.prepend do
          messages[i] = conf.prepend[i]  -- Deep copy instead of reference
      end
  end

Changes: Created new table instead of referencing conf.prepend

Fiexed issue: #12532

Which issue(s) this PR fixes:

Fixes #

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)