Strip fractional seconds in ParseDockerTimestamp#40495
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Pull request overview
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Copilot was unable to run its full agentic suite in this review.
Fixes parsing of Docker ISO 8601 timestamps that include fractional seconds by normalizing the input before std::chrono::parse, preventing valid timestamps (e.g. ...00.123456789Z) from throwing E_INVALIDARG.
Changes:
- Normalize Docker timestamps by stripping the optional fractional seconds portion before parsing.
- Keep existing
%Z-based parsing behavior while ensuring epoch-second precision remains correct.
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I'm not totally sold on this one. |
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Ok, I think I've convinced myself this is real and worth doing. |
The chrono parse format `%FT%H:%M:%S%Z` does not consume the optional fractional seconds component that Docker emits in ISO 8601 timestamps (e.g. `2026-03-05T10:30:00.123456789Z`). For timestamps with a fractional component the parse fails and `THROW_HR_IF_MSG` reports an `E_INVALIDARG` for what is in fact a valid Docker timestamp. Strip the fractional component (between `.` and the timezone marker `Z` / `+` / `-`) before parsing. The function returns epoch seconds, so the dropped sub-second precision is irrelevant. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The '.' itself can't match 'Z', '+' or '-', so starting find_first_of one past dot makes the intent slightly clearer and avoids an unnecessary comparison. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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| // We only need epoch seconds, so strip the optional fractional component before parsing. | ||
| std::string normalized = timestamp; | ||
| if (const auto tPos = normalized.find('T'); tPos != std::string::npos) | ||
| { | ||
| if (const auto dot = normalized.find('.', tPos + 1); dot != std::string::npos) |
OneBlue
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May 12, 2026
| // Docker timestamps are UTC ISO 8601, e.g. "2026-03-05T10:30:00.123456789Z". | ||
| // We only need epoch seconds, so strip the optional fractional component before parsing. | ||
| std::string normalized = timestamp; | ||
| if (const auto tPos = normalized.find('T'); tPos != std::string::npos) |
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Instead of doing this, I think we can just drop the %Z part of the format and std::chrono::parse() should just ignore the fractional second part
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Split out from #40489.
The chrono parse format
%FT%H:%M:%S%Zdoes not consume the optional fractional seconds component that Docker emits in ISO 8601 timestamps (e.g.2026-03-05T10:30:00.123456789Z). For timestamps with a fractional component the parse fails and the call throwsE_INVALIDARGfor what is actually a valid Docker timestamp.Change
src/windows/wslcsession/WSLCContainer.cpp: strip the optional fractional component (between.and the timezone markerZ/+/-) before parsing. The function returns epoch seconds, so dropping sub-second precision is correct.Validation
%Zparse forZ/ abbreviated zones still runs unchanged.2026-03-05T10:30:00Z— no., unchanged2026-03-05T10:30:00.123456789Z— fractional stripped beforeZ2026-03-05T10:30:00.123+05:00— fractional stripped before+