fix: duplicate startup warnings in admin panel

[alessandroferra]

Fixes #36630

Problem

StartupProblems warnings (from deprecatedSetting and other LogStartupProblem calls) appear twice in the admin panel at /-/admin and /-/admin/self_check.

LoadCommonSettings() is called twice during web server startup:

1. Early init via cmd/main.go → InitWorkPathAndCommonConfig → LoadCommonSettings()
2. Web server startup via cmd/web.go → serveInstalled → LoadCommonSettings()

The second call re-initializes the config provider first (InitCfgProvider), but StartupProblems and configuredPaths are never cleared between loads, so every warning gets appended twice.

Fix

Clear StartupProblems and configuredPaths at the start of LoadCommonSettings() so only the final load's warnings are retained.

This approach was chosen over clearing in InitCfgProvider because:

• Warnings are produced during settings load, not provider init
• Some callers set CfgProvider directly without calling InitCfgProvider
• It avoids coupling correctness to a specific call ordering

Screenshots

Result (single warning as expected):

testing

[x] Added TestLoadCommonSettingsClearsStartupProblems — verifies no duplicate messages after consecutive loads
[x] Added TestLoadCommonSettingsClearsConfiguredPaths — verifies path overlap map is identical after consecutive loads
[x] All existing modules/setting tests pass
[x] Manually verified in admin panel with deprecated [oauth2].ENABLE setting

[silverwind]

Comment written by Claude (AI assistant)

I reviewed this PR. The analysis of the double-call problem is correct:

1. cmd/main.go → InitWorkPathAndCommonConfig → LoadCommonSettings() (first call)
2. cmd/web.go → serveInstalled → InitCfgProvider + LoadCommonSettings() (second call)

StartupProblems and configuredPaths accumulate across both calls, causing duplicates.

The fix is minimal and placed correctly. Clearing at the start of LoadCommonSettings rather than in InitCfgProvider is the right call, since LogStartupProblem callers outside LoadCommonSettings (e.g. services/webtheme/webtheme.go) run later during web startup and their warnings won't be lost.

Two minor notes:

1. Using StartupProblems[:0] (reslice) instead of nil is fine — it reuses the underlying array on the next append, though for a startup-only slice the difference is negligible.

2. For configuredPaths, the clear is mainly about cleanliness. Without it, re-adding the same (path, name) pairs from the second load wouldn't trigger false overlap warnings (since checkOverlappedPath checks targetName != name), but it could mask a real overlap if a path's logical owner changed between loads. Clearing makes the final state deterministic regardless.

LGTM

[wxiaoguang]

I think I can spend more time on this to have a better fix (avoid duplicate calls)

I worry about the side effects of these duplicate calls, and I guess it is a problem caused by my code (introducing InitWorkPathAndCommonConfig to fix other problems)

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Will take a look when I get some time later. Thank you all.

[silverwind]

Yeah a root cause fix would be ideal, this is just a workaround.

[wxiaoguang]

The duplicate LoadCommonSettings call is caused by Refactor to use urfave/cli/v2 (#25959) & Refactor path & config system #25330

I think we need to remove the LoadCommonSettings in serveInstalled. Will try