Allow pull requests, and report correct commit oid and ref

lib/util.js

@@ -11,6 +11,7 @@ var __importDefault = (this && this.__importDefault) || function (mod) {
 };
 Object.defineProperty(exports, "__esModule", { value: true });
 const core = __importStar(require("@actions/core"));
+const exec = __importStar(require("@actions/exec"));
 const http = __importStar(require("@actions/http-client"));
 const auth = __importStar(require("@actions/http-client/auth"));
 const octokit = __importStar(require("@octokit/rest"));
@@ -33,12 +34,6 @@ function should_abort(actionName, requireInitActionHasRun) {
         core.setFailed('GITHUB_REF must be set.');
         return true;
     }
-    // Should abort if called on a merge commit for a pull request.
-    if (ref.startsWith('refs/pull/')) {
-        core.warning('The CodeQL ' + actionName + ' action is intended for workflows triggered on `push` events, '
-            + 'but the current workflow is running on a pull request. Aborting.');
-        return true;
-    }
     // If the init action is required, then check the it completed successfully.
     if (requireInitActionHasRun && process.env[sharedEnv.CODEQL_ACTION_INIT_COMPLETED] === undefined) {
         core.setFailed('The CodeQL ' + actionName + ' action cannot be used unless the CodeQL init action is run first. Aborting.');
@@ -151,6 +146,21 @@ async function getLanguages() {
     return languages;
 }
 exports.getLanguages = getLanguages;
+/**
+ * Gets the SHA of the commit that is currently checked out.
+ */
+async function getCommitOid() {
+    let commitOid = '';
+    await exec.exec('git', ['rev-parse', 'HEAD'], {
+        silent: true,
+        listeners: {
+            stdout: (data) => { commitOid += data.toString(); },
+            stderr: (data) => { process.stderr.write(data); }
+        }
+    });
+    return commitOid.trim();
+}
+exports.getCommitOid = getCommitOid;
 /**
  * Get the path of the currently executing workflow.
  */
@@ -196,8 +206,20 @@ exports.getAnalysisKey = getAnalysisKey;
  * Get the ref currently being analyzed.
  */
 function getRef() {
-    // it's in the form "refs/heads/master"
-    return getRequiredEnvParam('GITHUB_REF');
+    // Will be in the form "refs/heads/master" on a push event
+    // or in the form "refs/pull/N/merge" on a pull_request event
+    const ref = getRequiredEnvParam('GITHUB_REF');
+    // For pull request refs we want to convert from the 'merge' ref
+    // to the 'head' ref, as that is what we want to analyse.
+    // There should have been some code earlier in the workflow to do
+    // the checkout, but we have no way of verifying that here.
+    const pull_ref_regex = /refs\/pull\/(\d+)\/merge/;
+    if (pull_ref_regex.test(ref)) {
+        return ref.replace(pull_ref_regex, 'refs/pull/$1/head');
+    }
+    else {
+        return ref;
+    }
 }
 exports.getRef = getRef;
 /**