Defer bind dispatcher validation until plugins finish loading

[dskvr]

Note

This is in response to hyprwm#5247 and hyprwm#4373

I chose to isolate the PR here to avoid polluting upstream pull requests with an experiment that may not be welcomed since corresponding issue/discussion were closed. Will change base branch upon request.

Problem

• Binds referencing plugin-provided dispatchers (e.g., split:workspace) are parsed before plugins register those dispatchers.
• This yields noisy startup/reload errors like “Invalid dispatcher …”, which later disappear once plugins load and trigger a config reload.
• The noise desensitizes users to real errors and complicates plugin setups where binds must coexist with core fallbacks.

Proposal

• Make bind parsing tolerant to unknown dispatchers while plugins are still loading.
• Defer reporting of unknown dispatchers until plugin loads settle; then surface unresolved ones as a single, clear error message.
• Track config-driven plugin loads to know when the set of plugins has stabilized.

Changes

ConfigManager.cpp

• Bind parsing: unknown dispatcher no longer errors immediately; it is deferred.
  • File: src/config/ConfigManager.cpp (handleBind)
• Track and clear deferrals per reload cycle.
  • Added field: m_deferredUnknownDispatchers (vector)
  • Cleared in resetHLConfig().
• After handlePluginLoads() in postConfigReload, if no plugin loads are pending, surface all deferred unknown dispatchers as a single error and clear them.
  • Files: src/config/ConfigManager.cpp (postConfigReload), src/config/ConfigManager.hpp

PluginSystem.cpp

• Track in-flight config-declared plugin loads.
  • Added std::atomic<int> m_pendingConfigPluginLoads and accessor isLoadingConfigPlugins().
  • File: src/plugins/PluginSystem.hpp
• In updateConfigPlugins, count new plugins to load, increment the counter, decrement on completion (success/failure), and when the counter reaches zero schedule a cohesive g_pConfigManager->reload().
  • File: src/plugins/PluginSystem.cpp

Behavior

• On first parse, binds to plugin dispatchers are accepted without error and deferred.
• Once all config-declared plugins load (or fail) and the system stabilizes, any still-unknown dispatchers are reported once, clearly.
• No changes to existing configuration syntax or plugin APIs; plugins continue to register dispatchers via HyprlandAPI::addDispatcherV2.

Rationale vs Alternatives

• Avoids adding new config directives (e.g., “exec-after/source-after”) and avoids global reordering of parsing vs plugin loading.
• Keeps validation strict once plugins stabilize while removing spurious early errors.

Potential Issues / Trade-offs

• Delayed error reporting: typos in dispatcher names are surfaced after plugin loads settle, not immediately on first parse.
• verify may no longer fail purely on plugin dispatchers being absent (since plugins are not loaded in verify), which could hide plugin-related bind mistakes during verification. This could be resolved with a keyword that suppresses the deferred behavior or log-levels
• Manual (non-config) plugin loads are not tracked by the pending counter; a transient error could appear if deferrals are surfaced before a manual load completes. A subsequent reload will resolve it.
• One aggregated reload is scheduled after all config plugin loads finish; per-plugin load still schedules its own reload. This can result in extra reloads; optimizing to suppress per-plugin reloads for config-driven loads could be a follow-up.
• Deferred list is not deduplicated; repeated unknown names may appear more than once in the final message (kept simple for now).

Testing Notes

• With plugin=/path/to/plugin.so and binds to plugin dispatchers:
  • No startup “Invalid dispatcher …” spam.
  • After plugins load successfully, binds exist and work.
  • If a plugin fails or is removed, a single error lists the unresolved dispatchers after loads settle.
• Manual hyprctl plugin load still works; subsequent reload resolves binds.

Compatibility

• No breaking changes to existing configs or plugin interfaces.
• Minimal, isolated code paths; low maintenance overhead.

Test Script

• Run automated test script:
  • bash scripts/run_deferral_test.sh
  • Builds Hyprland and the hyprtester plugin, runs a nested Hyprland with an isolated config, captures logs, and asserts:
    • Deferral before plugin load for a valid plugin dispatcher.
    • Continued deferral for an intentionally unknown dispatcher.
    • No “Invalid dispatcher” spam on first parse.
  • Logs and temp config path are printed on success/failure for deeper inspection.