wallet: Validate all descriptors before importing in importdescriptors #34903

1. 
   HouseOfHufflepuff commented at 3:47 pm on March 23, 2026: none

   Summary

   • Extract descriptor validation into a separate ValidateDescriptorImport() function
   • Run a validation pass over all descriptors before importing any, so users get immediate error feedback without waiting for a potentially lengthy blockchain rescan
   • If any descriptor fails validation, return immediately — no wallet modifications or rescan are performed
   • Follows pinheadmz’s suggested approach from #33655: “separate the validation into a separate function entirely, so we validate in a loop first then process in a second loop”
   • There’s code duplication between ValidateDescriptorImport and the first half of ProcessDescriptorImport. Happy to consolidate if requested.
   • Addresses achow101’s concern from #33874: descriptors that were not actually imported never return success: true

   fixes #33655

   Test plan

   • New functional test in wallet_importdescriptors.py verifies batch validation behavior
   • All existing wallet_importdescriptors.py tests pass
   • Unit tests pass
2. wallet: Validate all descriptors before importing in importdescriptors

   Currently, importdescriptors validates and imports descriptors in a
   single loop, then rescans. If any descriptor has a validation error
   (e.g., internal descriptor with a label), the user only sees that
   error after the potentially lengthy rescan completes.
   
   Extract validation logic into a separate ValidateDescriptorImport()
   function and run it for all descriptors before any are imported. If
   any descriptor fails validation, return immediately with errors for
   all descriptors — no wallet modifications or rescan are performed.
   
   Descriptors that passed validation but were not imported (due to a
   sibling failing) are marked with success: false and a message
   explaining the batch was aborted.
   
   Add a functional test verifying the batch-validation-before-import
   behavior.
   
   fixes #33655

   5fa3aad68d
3. DrahtBot added the label Wallet on Mar 23, 2026
4. 
   DrahtBot commented at 3:48 pm on March 23, 2026: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Reviews

   See the guideline for information on the review process. A summary of reviews will appear here.

5. 
   HouseOfHufflepuff commented at 3:49 pm on March 23, 2026: none

   @murchandamus @yancyribbens

Contributors
HouseOfHufflepuff DrahtBot

Labels
Wallet