Add the ability to change directories before execing.

base/process/process_util_unittest.cc

Index: base/process/process_util_unittest.cc
diff --git a/base/process/process_util_unittest.cc b/base/process/process_util_unittest.cc
index 33cf00f31dce49628807adb7fa11448ccb2fdd88..e506352e822d5534528de807f86ff13bdf097972 100644
--- a/base/process/process_util_unittest.cc
+++ b/base/process/process_util_unittest.cc
@@ -1023,4 +1023,38 @@ TEST(ForkWithFlagsTest, UpdatesPidCache) {
   ASSERT_TRUE(WIFEXITED(status));
   EXPECT_EQ(kSuccess, WEXITSTATUS(status));
 }
+
+const char* kTmpDir = "/tmp";

[jln (very slow on Chromium), 2015/01/30 23:48:11]

Let's declare storage: const char kTmpDir[]

But you also need to change that since it won't work on Android (where you'd
need /data/local/tmp).

You should simply use GetTempDir()

[rickyz (no longer on Chrome), 2015/01/30 23:58:37]

Done, thanks for saving me a try failure :-)

+
+MULTIPROCESS_TEST_MAIN(CheckCwdProcess) {
+  const base::FilePath expected(kTmpDir);
+  base::FilePath actual;
+  CHECK(base::GetCurrentDirectory(&actual));
+  CHECK(actual == expected);
+  return kSuccess;
+}
+
+TEST_F(ProcessUtilTest, CurrentDirectory) {
+  base::LaunchOptions options;

[jln (very slow on Chromium), 2015/01/30 23:48:11]

I would change the CurrentDirectory to NOT the temp dir first.

[rickyz (no longer on Chrome), 2015/01/30 23:58:37]

I made this change, and tests seem to pass, but are you sure that no other tests
running in a different thread might depend on a certain cwd?

[jln (very slow on Chromium), 2015/01/31 00:21:55]

Tests are never run concurrently in threads. What happens in that sometimes
threads from other tests linger and create flakiness. If we make such threads
crash here that would be fine and catch a reason for flakiness: they should not
exist.

[rickyz (no longer on Chrome), 2015/01/31 00:59:37]

Removing this and adding a TODO as we discussed due to the SpawnChildWithOptions
relying on the current directory in this change.

+  options.current_directory = base::FilePath(kTmpDir);
+
+  base::Process process(SpawnChildWithOptions("CheckCwdProcess", options));
+  ASSERT_TRUE(process.IsValid());
+
+  int exit_code = 42;
+  EXPECT_TRUE(process.WaitForExit(&exit_code));
+  EXPECT_EQ(kSuccess, exit_code);
+}
+
+TEST_F(ProcessUtilTest, InvalidCurrentDirectory) {
+  base::LaunchOptions options;
+  options.current_directory = base::FilePath("/etc/passwd");
+
+  base::Process process(SpawnChildWithOptions("SimpleChildProcess", options));
+  ASSERT_TRUE(process.IsValid());
+
+  int exit_code = 42;
+  EXPECT_TRUE(process.WaitForExit(&exit_code));
+  EXPECT_EQ(-1, exit_code);
+}
 #endif