fix(windows): skip DPI awareness API call when already set via manifest

[leaanthony]

Summary

• Check current DPI awareness before calling SetProcessDpiAwarenessContext
• Windows only allows setting DPI awareness once per process - either via manifest or API, not both
• If already set (e.g., via application manifest in built binaries), skip the API call to avoid "Access is denied" errors

Problem

When using wails3 dev or running built binaries, users see the error:

SetProcessDpiAwarenessContext failed 0: 18446744073709551612 Access is denied.

This happens because:

1. Built binaries have a manifest file that sets DPI awareness
2. At runtime, setupDPIAwareness() tries to call SetProcessDpiAwarenessContext
3. Windows rejects the API call since DPI awareness was already configured

Solution

Added GetProcessDpiAwareness() to query the current DPI awareness level before attempting to set it. If awareness is already configured (not PROCESS_DPI_UNAWARE), the API call is skipped.

Test plan

• Build a Wails app with wails3 build and verify no DPI error appears
• Run with go run and verify DPI awareness is correctly set via API
• Test on Windows 10/11 with various DPI settings

Fixes #4803

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Fixed "Access is denied" error that occurred during application startup when DPI awareness was already configured through the application manifest. The application now checks for existing DPI awareness settings before attempting reconfiguration, preventing redundant configuration attempts and associated access denial errors.

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📥 Commits

Reviewing files that changed from the base of the PR and between d216776 and 9d82164.

📒 Files selected for processing (3)

• v3/UNRELEASED_CHANGELOG.md (1 hunks)
• v3/pkg/application/application_windows.go (1 hunks)
• v3/pkg/w32/shcore.go (1 hunks)

Walkthrough

This PR fixes an "Access is denied" error in SetProcessDpiAwarenessContext by adding a pre-check to determine if DPI awareness is already set via application manifest. If detected, the setup returns early, preventing redundant configuration. The fix includes new Windows API bindings for GetProcessDpiAwareness.

Changes

Cohort / File(s)	Summary
Changelog entry v3/UNRELEASED_CHANGELOG.md	Documents bug fix for SetProcessDpiAwarenessContext "Access is denied" error
DPI awareness pre-check v3/pkg/application/application_windows.go	Adds early-return logic in setupDPIAwareness to skip DPI configuration if awareness is already set via manifest
Windows API bindings v3/pkg/w32/shcore.go	Introduces HasGetProcessDpiAwarenessFunc() and GetProcessDpiAwareness() to query current DPI awareness state from shcore.dll

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

• Windows API binding declarations in shcore.go should be verified for correctness and proper error handling
• Early-return logic in application_windows.go should be confirmed to handle all DPI awareness states correctly

Suggested labels

Bug, Windows, go, v3-alpha, size:M, lgtm

Poem

🐰 Hop, check, and return!
When DPI awareness is already set,
No need to call again with regret—
A pre-flight check saves the day,
No more "Access denied" in the way! ✨

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: adding a check to skip DPI awareness API calls when already set via manifest, which directly addresses the fix for issue #4803.
Description check	✅ Passed	The description includes a clear summary of the problem and solution, references the fixed issue (#4803), and provides a test plan. Most template sections are addressed, though some checklist items are not explicitly confirmed.
Linked Issues check	✅ Passed	The PR successfully addresses issue #4803 by implementing GetProcessDpiAwareness() to check current DPI awareness and skip redundant API calls, preventing 'Access is denied' errors when DPI awareness is already set via application manifest.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing the DPI awareness issue: additions to the Windows bindings (w32/shcore.go), modifications to DPI setup logic (application_windows.go), and changelog documentation.

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Deploying wails with    Cloudflare Pages

Latest commit:	d216776
Status:	🚫  Build failed.

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud