src: unlink compile cache temp file on persist failure

src/compile_cache.cc

@@ -464,6 +464,23 @@ void CompileCacheHandler::Persist() {
       continue;
     }
     Debug(" -> %s\n", mkstemp_req.path);
+
+    // Avoid leaking the descriptor or the temporary file if persistence
+    // does not complete below.
+    bool tmp_fd_needs_close = true;
+    bool tmp_renamed = false;
+    auto cleanup_tmp_file = OnScopeLeave([&]() {
+      if (tmp_fd_needs_close) {
+        uv_fs_t req;
+        uv_fs_close(nullptr, &req, mkstemp_req.result, nullptr);
+        uv_fs_req_cleanup(&req);
+      }
+      if (!tmp_renamed) {
+        uv_fs_t req;
+        uv_fs_unlink(nullptr, &req, mkstemp_req.path, nullptr);
+        uv_fs_req_cleanup(&req);
+      }
+    });
     Debug("[compile cache] writing cache for %s %s to temporary file %s [%d "
           "%d %d "
           "%d %d]...",
@@ -496,6 +513,7 @@ void CompileCacheHandler::Persist() {
     auto cleanup_close =
         OnScopeLeave([&close_req]() { uv_fs_req_cleanup(&close_req); });
     err = uv_fs_close(nullptr, &close_req, mkstemp_req.result, nullptr);
+    tmp_fd_needs_close = false;
 
     if (err < 0) {
       Debug("failed: %s\n", uv_strerror(err));
@@ -521,6 +539,7 @@ void CompileCacheHandler::Persist() {
       Debug("failed: %s\n", uv_strerror(err));
       continue;
     }
+    tmp_renamed = true;
     Debug("success\n");
     entry->persisted = true;
   }

test/parallel/test-compile-cache-write-failure.js

@@ -0,0 +1,31 @@
+'use strict';
+
+// This tests that a compile cache persistence failure does not leave the
+// temporary file used to write it behind.
+
+const common = require('../common');
+if (common.isWindows)
+  common.skip('no RLIMIT_FSIZE on Windows');
+if (process.config.variables.node_shared)
+  common.skip('SIGXFSZ signal handler not installed in shared library mode');
+
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+const { spawnSync } = require('child_process');
+const tmpdir = require('../common/tmpdir');
+
+tmpdir.refresh();
+const cacheDir = tmpdir.resolve('compile_cache');
+fs.writeFileSync(tmpdir.resolve('fixture.cjs'), 'module.exports = 42;\n');
+
+const [cmd, opts] = common.escapePOSIXShell`ulimit -f 0 && "${process.execPath}" -e "require('./fixture.cjs')"`;
+opts.env.NODE_COMPILE_CACHE = cacheDir;
+opts.cwd = tmpdir.path;
+const result = spawnSync('/bin/sh', ['-c', cmd], opts);
+assert.strictEqual(result.status, 0, result.stderr.toString());
+
+const subdirs = fs.readdirSync(cacheDir);
+assert.strictEqual(subdirs.length, 1);
+const leftover = fs.readdirSync(path.join(cacheDir, subdirs[0]));
+assert.deepStrictEqual(leftover, []);