[dhairyajangir]

A missing block-upload end response previously called a nonexistent stream abort(), masking the communication timeout with AttributeError and sending no abort. This change calls the SDO client abort helper and re-raises the original timeout.

It also includes the requested object index/subindex in client aborts throughout expedited, segmented and block transfers. Each stream retains its original address before its first request; timeout and error paths use that context rather than interpreting segment payload bytes as an address. Retries, incoming remote-abort handling, abort reasons and COB IDs are preserved.

Existing abort() and abort(code) calls retain their defaults; direct calls without address context still use zero. The new address arguments are keyword-only. Subclasses overriding abort or request_response with narrower signatures must accept/forward these keywords; this requirement is documented.

Local Linux validation:

• Python 3.9 and 3.12: all 45 focused cases and four real two-endpoint VirtualBus exchanges passed on each version.
• Python 3.12: complete configured feature profiles passed: 325 tests plus one optional PDO-export skip, and 326 tests with db_export enabled.
• make -C doc html passed without observed warnings.
• Optional mypy still reports 44 errors in seven files, byte-identical to the previous PR head.

These results do not establish physical-device or strict-address-checking peer compatibility. Hosted CI has not run for this revision: the Python package run is action_required. Please authorize that run for the configured upstream tests and docs.

Fixes #377. Follow-up to #594.

AI assisted with investigation, the patch, and testing.

[dhairyajangir]

Scope update: this PR now also addresses #377, while retaining the original block-upload end-timeout fix. All internal stream abort and request/timeout paths carry the originally requested index/subindex. The 0x1008:00 end-timeout regression now expects 80 08 10 00 00 00 04 05, replacing the earlier helper's zero-address frame.

Legacy abort()/abort(code) defaults remain unchanged; explicit address arguments are keyword-only, and narrower subclass overrides must accept/forward them. The updated regression matrix and four two-endpoint VirtualBus exchanges passed on Python 3.9 and 3.12. These are local software-bus results; physical CAN and a device that validates abort addresses were not tested. Full local feature-profile results and the unchanged optional mypy failures are recorded in the PR body.

Codex assisted with this investigation, update and testing.