[crystalsighting]

Fixes qwen image 2.1 on webui so that sd-server with --sigmas "qwen-image-2.1-turbo" works when generating from webui, or any sigma you want.

Checklist

• I have read and confirmed this PR follows the contribution guidelines.

Summary by CodeRabbit

• Bug Fixes
  • Empty custom_sigmas arrays no longer override server or command-line defaults.
  • Non-empty custom_sigmas arrays continue to replace the configured sigma values.

[coderabbitai]

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ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Repository UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 0da6f827-f471-4c3c-84ad-ced073df1fcb

📥 Commits

Reviewing files that changed from the base of the PR and between b13a482 and 836fd8e.

📒 Files selected for processing: 1

• examples/common/common.cpp

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📝 Walkthrough

The JSON parser now ignores empty custom_sigmas arrays. Non-empty arrays still replace the target sigma values.

Changes: Custom sigma JSON handling

Layer / File(s)	Summary
Apply non-empty custom sigma arrays examples/common/common.cpp	The parser loads custom_sigmas only when it is an array with at least one element. Empty arrays no longer overwrite existing sigma settings.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~5 minutes

Change: Bug fix

Suggested reviewers: leejet

Merge Risk: ⚪ Minimal · up to 836fd

The sigma handling change matches the stated behavior and presents no actionable merge-blocking risk.

Architecture Summary

Architecture risk: 🔵 Low · up to 836fd

The change affects 1 system.

Changed systems: examples

Architecture concerns
No architecture-level concerns identified.

Review details

Systems and components

• observed — examples (service) was modified; 1 changed file maps to changed impact.

Before / after behavior

• observed — Modified behavior in examples/common/common.cpp: custom_sigmas is now loaded only when the JSON value is an array containing at least one element; empty arrays no longer overwrite existing or default sigma settings.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Title check		The title clearly describes the fix to --sigmas handling for Qwen Image 2.1 in sd-server and webui.
Description check		The description explains the change and expected behavior, and it includes the completed checklist. The optional Related Issue / Discussion and Additional Information sections are not included.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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