Fail InstallAndroidDependencies cleanly when ResolveAndroidTooling has no resolved SDK

[Copilot]

Fixes #11394

InstallAndroidDependencies could exit successfully even when a required platform package was still missing. On a fresh SDK/JDK path, ResolveAndroidTooling and ValidateJavaVersion could dereference unresolved SDK state and throw NullReferenceException/ArgumentNullException (surfaced as XARAT7001 / XAVJV7001), leaving dependency installation to continue as warnings instead of producing a hard failure.

ResolveAndroidTooling

• Now checks that SDK resolution actually produced a usable MonoAndroidHelper.AndroidSdk and AndroidSdkPath before probing build-tools / cmdline-tools paths.
• When that state is missing, the task logs the standard XA5300 Android SDK error and returns false instead of throwing XARAT7001 from a NullReferenceException.

var androidSdk = MonoAndroidHelper.AndroidSdk;
if (androidSdk == null || AndroidSdkPath.IsNullOrEmpty ()) {
    Log.LogCodedError ("XA5300", Properties.Resources.XA5300_Android_SDK);
    return false;
}

ValidateJavaVersion

• GetVersionFromTool / GetVersionFromFile previously threw ArgumentNullException (surfaced as XAVJV7001) when JavaSdkPath was null, because Path.Combine (JavaSdkPath, ...) was called unguarded.
• GetVersionFromTool now logs XA5300 (Java SDK directory could not be found) and returns null so Execute() fails deterministically.
• GetVersionFromFile only falls back to Path.Combine (JavaSdkPath, "release") when JavaSdkPath is set.

Why this matters

• InstallAndroidDependencies now gets a real task failure signal when SDK or JDK tooling resolution has not succeeded.
• This prevents the previous "warning chain + exit 0" behavior that allowed missing required packages such as platforms;android-37.0 to surface only later as XA5207.

Focused coverage

• ResolveSdksTaskTests: regression test asserting ResolveAndroidTooling:
  • fails deterministically when the resolved SDK state is missing,
  • still computes AndroidApiLevel for dependency resolution,
  • reports XA5300,
  • does not report XARAT7001.
• ValidateJavaVersionTests: NullJavaSdkPathDoesNotThrow and NullJavaSdkPathWithReleaseFileDoesNotThrow cover both the UseJavaExeVersion=true and UseJavaExeVersion=false code paths and assert Execute() returns false without emitting XAVJV7001.

[jonathanpeppers]

/review

[github-actions]

✅ Android PR Reviewer completed successfully!

[Copilot]

Pull request overview

Fixes InstallAndroidDependencies to fail cleanly when ResolveAndroidTooling runs without a resolved Android SDK, replacing a NullReferenceException-derived XARAT7001 with the proper XA5300 error.

Changes:

• In ResolveAndroidTooling.RunTask, validate MonoAndroidHelper.AndroidSdk and AndroidSdkPath after computing AndroidApiLevel, logging XA5300 and returning false when unavailable.
• Replace MonoAndroidHelper.AndroidSdk accesses with the locally captured androidSdk variable.
• Add a task-level regression test that nulls out MonoAndroidHelper.AndroidSdk and asserts deterministic failure with XA5300 (and no XARAT7001).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Xamarin.Android.Build.Tasks/Tasks/ResolveAndroidTooling.cs	Guards against null AndroidSdk/empty AndroidSdkPath before probing tooling paths and emits XA5300.
src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Tasks/ResolveSdksTaskTests.cs	Adds NUnit test validating the new failure path while preserving AndroidApiLevel computation.

[github-actions]

✅ LGTM — Clean, focused fix with good regression coverage.

Summary:

• The null guard correctly prevents the NullReferenceException → XARAT7001 cascade by checking MonoAndroidHelper.AndroidSdk and AndroidSdkPath before dereferencing.
• Intentionally places the guard after AndroidApiLevel computation so InstallAndroidDependencies still gets the API level for dependency resolution — smart design.
• Local androidSdk variable eliminates repeated static field access — good practice.
• Formatting fix (new [] {) aligns with Mono style.
• Test properly isolates the scenario, verifies both positive (XA5300 logged) and negative (XARAT7001 not thrown) conditions, and restores global state in finally.

CI: All checks passing ✅

Issue count: 0 ❌ · 0 ⚠️ · 1 💡

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