Avoid null dereference when testing an already-built QEMU PR

Author: arichardson

test/CheckCheribuildProjects.groovy

@@ -24,7 +24,7 @@ class CheckCheribuildProjects extends BaseRegressionTest {
     @Test
     void qemu_test() throws Exception {
 //        def script = loadScript("test-scripts/qemu.groovy")
-//        script.run()
+//        script.run()[
 //        printCallStack()
         CommonTestHelper.addEnvVars(this, ["JOB_NAME": "QEMU/qemu-cheri"])
         def script = runScript("test-scripts/qemu.groovy")
@@ -33,6 +33,32 @@ class CheckCheribuildProjects extends BaseRegressionTest {
         assertJobStatusUnstable()
     }
 
+    @Test
+    void qemu_pr_test_run() throws Exception {
+        CommonTestHelper.addEnvVars(this, ["JOB_NAME": "QEMU/qemu-cheri", "CHANGE_ID": "12"])
+        binding.setVariable('pullRequest', [
+                labels : [],
+                commits: [[sha: "12345abc", statuses: []]]
+        ])
+        // Normal run should work
+        runScript("test-scripts/qemu.groovy")
+        printCallStack()
+        assertJobStatusUnstable()
+    }
+
+    @Test
+    void qemu_pr_test_skipped() throws Exception {
+        // Regression test for a null dereference when skipping PR builds
+        CommonTestHelper.addEnvVars(this, ["JOB_NAME": "QEMU/qemu-cheri", "CHANGE_ID": "12"])
+        binding.setVariable('pullRequest', [
+                labels : ['NO-JENKINS'],
+                commits: [[sha: "12345abc", statuses: []]]
+        ])
+        runScript("test-scripts/qemu.groovy")
+        printCallStack()
+        assertJobStatusSuccess()
+    }
+
     @Test
     void llvm_test() throws Exception {
         CommonTestHelper.addEnvVars(this, [JOB_NAME   : "CLANG-LLVM-linux/dev",

vars/cheribuildProject.groovy

@@ -741,7 +741,10 @@ def call(Map args) {
 	}
 	def tasks = [:]
 	boolean shouldBuild = false
-	def skippedBuildTask = { -> echo "Not building this pull request." }
+	def skippedBuildTask = { params ->
+		echo "Not building this pull request."
+		return params
+	}
 	taskArgs.each { key, val ->
 		def params = parseParams(val)
 		if (env.CHANGE_ID && !shouldBuildPullRequest(context: params.gitHubStatusContext)) {
@@ -752,7 +755,7 @@ def call(Map args) {
 		tasks[key] = { -> return runCheribuild(params) }
 	}
 	if (!shouldBuild) {
-		return skippedBuildTask()
+		return skippedBuildTask([:])
 	}
 	if (singleArch) {
 		assert tasks.size() == 1