fix(safe-outputs): bridge git safe.directory trust via GIT_CONFIG_* env vars

actions/setup/js/git_helpers.cjs

@@ -37,6 +37,42 @@ function getGitAuthEnv(token) {
   };
 }
 
+/**
+ * Ensure the given directory is trusted for git in the current process context.
+ * Injects safe.directory via GIT_CONFIG_COUNT/KEY/VALUE env vars so that all
+ * subsequent git commands in this process inherit the trust without writing to
+ * ~/.gitconfig (no persistent global git config side effects).
+ *
+ * This is specifically needed for the "bridge" path (the Process Safe Outputs step
+ * running outside the Docker container) where HOME or the uid may differ from the
+ * in-container user that originally configured safe.directory in ~/.gitconfig.
+ *
+ * GIT_CONFIG_COUNT/KEY/VALUE is supported since git 2.31.
+ *
+ * @param {string} gitCwd - The directory to trust (e.g. GITHUB_WORKSPACE or a repo checkout path)
+ * @returns {void}
+ */
+function ensureSafeDirectoryTrust(gitCwd) {
+  if (!gitCwd) return;
+
+  // Check if gitCwd is already present in the injected env-var config to avoid
+  // duplicate entries when the handler is called more than once in the same process.
+  // The `|| 0` guard converts NaN (from a malformed pre-existing GIT_CONFIG_COUNT) to 0,
+  // preventing GIT_CONFIG_KEY_NaN/VALUE_NaN entries that would corrupt the env-var config chain.
+  const existingCount = parseInt(process.env.GIT_CONFIG_COUNT || "0", 10) || 0;
+  for (let i = 0; i < existingCount; i++) {
+    if (process.env[`GIT_CONFIG_KEY_${i}`] === "safe.directory" && process.env[`GIT_CONFIG_VALUE_${i}`] === gitCwd) {
+      return;
+    }
+  }
+
+  const idx = existingCount;
+  process.env.GIT_CONFIG_COUNT = String(existingCount + 1);
+  process.env[`GIT_CONFIG_KEY_${idx}`] = "safe.directory";
+  process.env[`GIT_CONFIG_VALUE_${idx}`] = gitCwd;
+  core.debug(`Configured git safe.directory for bridge context: ${gitCwd}`);
+}
+
 /**
  * Safely execute git command using spawnSync with args array to prevent shell injection.
  *
@@ -603,6 +639,7 @@ async function linearizeRangeAsCommit(baseRef, commitMessage, execApi, opts = {}
 }
 
 module.exports = {
+  ensureSafeDirectoryTrust,
   execGitSync,
   backfillCommitObjects,
   ensureFullHistoryForBundle,

actions/setup/js/git_helpers.test.cjs

@@ -282,6 +282,114 @@ describe("git_helpers.cjs", () => {
     });
   });
 
+  describe("ensureSafeDirectoryTrust", () => {
+    let originalEnv;
+
+    beforeEach(() => {
+      originalEnv = { ...process.env };
+      // Clean up GIT_CONFIG_* vars injected by a previous test
+      for (const key of Object.keys(process.env)) {
+        if (key.startsWith("GIT_CONFIG_")) {
+          delete process.env[key];
+        }
+      }
+    });
+
+    afterEach(() => {
+      // Restore to original, removing any vars added during the test
+      for (const key of Object.keys(process.env)) {
+        if (!(key in originalEnv)) {
+          delete process.env[key];
+        }
+      }
+      Object.assign(process.env, originalEnv);
+    });
+
+    it("should export ensureSafeDirectoryTrust function", async () => {
+      const { ensureSafeDirectoryTrust } = await import("./git_helpers.cjs");
+      expect(typeof ensureSafeDirectoryTrust).toBe("function");
+    });
+
+    it("should set GIT_CONFIG_* env vars for the given directory", async () => {
+      const { ensureSafeDirectoryTrust } = await import("./git_helpers.cjs");
+
+      ensureSafeDirectoryTrust("/workspace/repo");
+
+      expect(process.env.GIT_CONFIG_COUNT).toBe("1");
+      expect(process.env.GIT_CONFIG_KEY_0).toBe("safe.directory");
+      expect(process.env.GIT_CONFIG_VALUE_0).toBe("/workspace/repo");
+    });
+
+    it("should not add a duplicate entry when called twice with the same directory", async () => {
+      const { ensureSafeDirectoryTrust } = await import("./git_helpers.cjs");
+
+      ensureSafeDirectoryTrust("/workspace/repo");
+      ensureSafeDirectoryTrust("/workspace/repo");
+
+      expect(process.env.GIT_CONFIG_COUNT).toBe("1");
+    });
+
+    it("should append a new entry when called with a different directory", async () => {
+      const { ensureSafeDirectoryTrust } = await import("./git_helpers.cjs");
+
+      ensureSafeDirectoryTrust("/workspace/repo-a");
+      ensureSafeDirectoryTrust("/workspace/repo-b");
+
+      expect(process.env.GIT_CONFIG_COUNT).toBe("2");
+      expect(process.env.GIT_CONFIG_KEY_0).toBe("safe.directory");
+      expect(process.env.GIT_CONFIG_VALUE_0).toBe("/workspace/repo-a");
+      expect(process.env.GIT_CONFIG_KEY_1).toBe("safe.directory");
+      expect(process.env.GIT_CONFIG_VALUE_1).toBe("/workspace/repo-b");
+    });
+
+    it("should be a no-op when called with an empty string", async () => {
+      const { ensureSafeDirectoryTrust } = await import("./git_helpers.cjs");
+
+      ensureSafeDirectoryTrust("");
+
+      expect(process.env.GIT_CONFIG_COUNT).toBeUndefined();
+    });
+
+    it("should be a no-op when called with undefined/falsy", async () => {
+      const { ensureSafeDirectoryTrust } = await import("./git_helpers.cjs");
+
+      ensureSafeDirectoryTrust(undefined);
+
+      expect(process.env.GIT_CONFIG_COUNT).toBeUndefined();
+    });
+
+    it("should preserve existing GIT_CONFIG_* entries set by getGitAuthEnv", async () => {
+      const { ensureSafeDirectoryTrust, getGitAuthEnv } = await import("./git_helpers.cjs");
+
+      // Simulate what getGitAuthEnv returns being already applied via env
+      const authEnv = getGitAuthEnv("test-token");
+      Object.assign(process.env, authEnv);
+
+      ensureSafeDirectoryTrust("/workspace/repo");
+
+      // The count should be incremented by 1 (from 1 to 2)
+      expect(parseInt(process.env.GIT_CONFIG_COUNT, 10)).toBe(2);
+      // Existing auth entry preserved
+      expect(process.env.GIT_CONFIG_KEY_0).toBe(authEnv.GIT_CONFIG_KEY_0);
+      expect(process.env.GIT_CONFIG_VALUE_0).toBe(authEnv.GIT_CONFIG_VALUE_0);
+      // New safe.directory entry appended
+      expect(process.env.GIT_CONFIG_KEY_1).toBe("safe.directory");
+      expect(process.env.GIT_CONFIG_VALUE_1).toBe("/workspace/repo");
+    });
+
+    it("should handle a malformed GIT_CONFIG_COUNT gracefully", async () => {
+      const { ensureSafeDirectoryTrust } = await import("./git_helpers.cjs");
+
+      process.env.GIT_CONFIG_COUNT = "not-a-number";
+
+      ensureSafeDirectoryTrust("/workspace/repo");
+
+      expect(process.env.GIT_CONFIG_COUNT).toBe("1");
+      expect(process.env.GIT_CONFIG_KEY_0).toBe("safe.directory");
+      expect(process.env.GIT_CONFIG_VALUE_0).toBe("/workspace/repo");
+    });
+  });
+
   describe("ensureFullHistoryForBundle", () => {
     it("should unshallow the repository when the repository is shallow", async () => {
       const { ensureFullHistoryForBundle } = await import("./git_helpers.cjs");

actions/setup/js/push_to_pull_request_branch.cjs

@@ -18,7 +18,7 @@ const { checkFileProtection, checkFileProtectionPostApply } = require("./manifes
 const { buildWorkflowRunUrl } = require("./workflow_metadata_helpers.cjs");
 const { renderTemplateFromFile, buildProtectedFileList, getPromptPath } = require("./messages_core.cjs");
 const { overridePersistedExtraheader, restorePersistedExtraheader } = require("./git_auth_helpers.cjs");
-const { ensureFullHistoryForBundle, extractBundlePrerequisiteCommits, isShallowOrSparseCheckout, linearizeRangeAsCommit } = require("./git_helpers.cjs");
+const { ensureFullHistoryForBundle, extractBundlePrerequisiteCommits, isShallowOrSparseCheckout, linearizeRangeAsCommit, ensureSafeDirectoryTrust } = require("./git_helpers.cjs");
 const { normalizeCommitSHA } = require("./commit_sha_helpers.cjs");
 const { findRepoCheckout } = require("./find_repo_checkout.cjs");
 const { getThreatDetectedMarker } = require("./threat_detection_warning.cjs");
@@ -326,6 +326,13 @@ async function main(config = {}) {
   const { defaultTargetRepo, allowedRepos } = resolveTargetRepoConfig(config);
   const githubClient = await createAuthenticatedGitHubClient(config);
 
+  // Ensure the workspace is trusted in the bridge process (Process Safe Outputs step).
+  // The bridge runs outside the Docker container as a potentially different user/HOME,
+  // so the in-container `git config --global safe.directory` may not be visible here.
+  // Using GIT_CONFIG_* env vars avoids relying on ~/.gitconfig and covers cases where
+  // the conditional "Configure Git credentials" step was skipped or HOME differs.
+  ensureSafeDirectoryTrust(process.env.GITHUB_WORKSPACE || process.cwd());
+
   // Git network operations authenticate using the credentials actions/checkout
   // persisted into .git/config for the safe_outputs job (persist-credentials: true,
   // using the resolved push token). We intentionally do NOT inject an additional
@@ -667,6 +674,12 @@ async function main(config = {}) {
 
     // Base options for all git exec calls - includes cwd when running in a subdirectory checkout
     const baseGitOpts = repoCwd ? { cwd: repoCwd } : {};
+
+    // For cross-repo checkouts, also trust the specific subdirectory. The factory-level call
+    // covers GITHUB_WORKSPACE; this per-message call covers subdirectory checkout paths.
+    if (repoCwd) {
+      ensureSafeDirectoryTrust(repoCwd);
+    }
     let pullRequest;
     try {
       const response = await githubClient.rest.pulls.get({
@@ -1106,7 +1119,7 @@ async function main(config = {}) {
           } catch {
             // Ignore
           }
-          return { success: false, error: "Failed to apply bundle" };
+          return { success: false, error: `Failed to apply bundle: ${getErrorMessage(bundleError)}` };
         }
       } else {
         // Patch transport (non-default): git am --3way

actions/setup/js/safe_outputs_handlers.cjs

@@ -13,7 +13,7 @@
 const { lookupCheckout } = require("./checkout_manifest.cjs");
 const { generateGitPatch } = require("./generate_git_patch.cjs");
 const { generateGitBundle } = require("./generate_git_bundle.cjs");
-const { hasMergeCommitsInRange, execGitSync } = require("./git_helpers.cjs");
+const { hasMergeCommitsInRange, execGitSync, ensureSafeDirectoryTrust } = require("./git_helpers.cjs");
 const { enforceCommentLimits } = require("./comment_limit_helpers.cjs");
 const { getErrorMessage } = require("./error_helpers.cjs");
 const { ERR_CONFIG, ERR_SYSTEM, ERR_VALIDATION } = require("./error_codes.cjs");
@@ -200,39 +200,6 @@
   return { success: true, absolutePath: resolved };
 }
 
-/**
- * Ensure the current git checkout path is trusted in this process context.
- * Injects safe.directory via GIT_CONFIG_COUNT/KEY/VALUE env vars so that all
- * subsequent git commands in this process inherit the trust without writing to
- * ~/.gitconfig (no persistent global git config side effects).
- *
- * GIT_CONFIG_COUNT/KEY/VALUE is supported since git 2.31.
- *
- * @param {string} gitCwd
- * @param {{ debug: (message: string) => void }} server
- * @returns {void}
- */
-function ensureSafeDirectoryTrust(gitCwd, server) {
-  if (!gitCwd) return;
-
-  // Check if gitCwd is already present in the injected env-var config to avoid
-  // duplicate entries when the handler is called more than once in the same process.
-  // The `|| 0` guard converts NaN (from a malformed pre-existing GIT_CONFIG_COUNT) to 0,
-  // preventing GIT_CONFIG_KEY_NaN/VALUE_NaN entries that would corrupt the env-var config chain.
-  const existingCount = parseInt(process.env.GIT_CONFIG_COUNT || "0", 10) || 0;
-  for (let i = 0; i < existingCount; i++) {
-    if (process.env[`GIT_CONFIG_KEY_${i}`] === "safe.directory" && process.env[`GIT_CONFIG_VALUE_${i}`] === gitCwd) {
-      return;
-    }
-  }
-
-  const idx = existingCount;
-  process.env.GIT_CONFIG_COUNT = String(existingCount + 1);
-  process.env[`GIT_CONFIG_KEY_${idx}`] = "safe.directory";
-  process.env[`GIT_CONFIG_VALUE_${idx}`] = gitCwd;
-  server.debug(`Configured git safe.directory for bridge context: ${gitCwd}`);
-}
-
 /**
  * Create handlers for safe output tools
  * @param {Object} server - The MCP server instance for logging
@@ -244,7 +211,7 @@
   // Ensure the workspace is trusted for the lifetime of this server process.
   // This covers all current and future handlers automatically; per-handler calls
   // additionally cover per-request checkout paths that differ from GITHUB_WORKSPACE.
-  ensureSafeDirectoryTrust(process.env.GITHUB_WORKSPACE || process.cwd(), server);
+  ensureSafeDirectoryTrust(process.env.GITHUB_WORKSPACE || process.cwd());
 
   const TOKEN_THRESHOLD = 16000;
 
@@ -802,7 +769,7 @@
     // This prevents TOCTOU races where the agent flips the ref between patch and bundle
     // generation, causing the two to represent different commit sets.
     const gitCwd = repoCwd || process.env.GITHUB_WORKSPACE || process.cwd();
-    ensureSafeDirectoryTrust(gitCwd, server);
+    ensureSafeDirectoryTrust(gitCwd);
     let pinnedSha;
     try {
       pinnedSha = execGitSync(["rev-parse", "--verify", `refs/heads/${entry.branch}^{commit}`], { cwd: gitCwd })
@@ -1238,7 +1205,7 @@
     // This prevents TOCTOU races where the agent flips the ref between patch and bundle
     // generation, causing the two to represent different commit sets.
     const pushGitCwd = repoCwd || process.env.GITHUB_WORKSPACE || process.cwd();
-    ensureSafeDirectoryTrust(pushGitCwd, server);
+    ensureSafeDirectoryTrust(pushGitCwd);
     let pushPinnedSha;
     try {
       pushPinnedSha = execGitSync(["rev-parse", "--verify", `refs/heads/${entry.branch}^{commit}`], { cwd: pushGitCwd })