--- /dev/null
+++ Libc/Libc-1725.40.4/tests/execvp.c
@@ -0,0 +1,646 @@
+#include <sys/wait.h>
+#include <assert.h>
+#include <copyfile.h>
+#include <paths.h>
+#include <unistd.h>
+
+#include <darwintest.h>
+#include <darwintest_utils.h>
+#include <darwintest_posix.h>
+
+T_GLOBAL_META(T_META_RUN_CONCURRENTLY(true));
+
+/*
+ * Create copy of a program in the given directory.  Returns an open
+ * descriptor to the newly created program.  Any error other than a
+ * failure to create the file results in SIGABRT.
+ */
+static int
+_copy_program_impl(const char *template, int dd, const char *name, mode_t perm)
+{
+	int pd, td;
+	int serrno;
+
+	(void)unlinkat(dd, name, 0);
+	pd = openat(dd, name, O_RDWR|O_CREAT|O_TRUNC, 0600);
+	if (pd < 0) {
+		serrno = errno;
+		(void)close(dd);
+		errno = serrno;
+		return (pd);
+	}
+	assert(fchmod(pd, perm) == 0);
+	assert((td = open(template, O_RDONLY)) >= 0);
+	assert(fcopyfile(td, pd, NULL, COPYFILE_DATA) == 0);
+	assert(close(td) == 0);
+	return (pd);
+}
+static int
+_copy_program(const char *template, const char *dir, const char *name, mode_t perm)
+{
+	int dd, pd, serrno;
+
+	assert((dd = open(dir, O_RDONLY)) >= 0);
+	pd = _copy_program_impl(template, dd, name, perm);
+	serrno = errno;
+	assert(close(dd) == 0);
+	errno = serrno;
+
+	return (pd);
+}
+
+/*
+ * Fork a child which invokes execvp() with the arguments provided by the
+ * caller.  The provided search path, if not NULL, is used instead of
+ * $PATH.  If the call fails, the child reports the outcome by writing the
+ * return value and the value of errno to a pipe to the parent.  The
+ * parent sets errno to the reported value and returns the reported return
+ * value.  If the call succeeds, the parent sets errno to 0 and returns 0.
+ * If statusp is not NULL, it will contain the child's wait status.  Any
+ * unexpected situation (failure to set up the reporting pipe, failure to
+ * fork, unexpected return value from waitpid(), etc.) results in SIGABRT.
+ */
+static int
+_fork_execvp(const char *name, char *const args[], const char *search_path,
+    int *statusp)
+{
+	struct { int ret, err; } report;
+	ssize_t sz;
+	pid_t pid;
+	int p[2], status;
+
+	if (search_path == NULL)
+		search_path = getenv("PATH");
+	if (search_path == NULL)
+		search_path = _PATH_DEFPATH;
+	report.ret = report.err = status = 0;
+	assert(pipe(p) == 0);
+	assert(fcntl(p[0], F_SETFD, FD_CLOEXEC) == 0);
+	assert(fcntl(p[1], F_SETFD, FD_CLOEXEC) == 0);
+	assert((pid = fork()) >= 0);
+	if (pid == 0) {
+		/* child */
+		errno = 0;
+		report.ret = execvP(name, search_path, args);
+		report.err = errno;
+		(void)write(p[1], &report, sizeof(report));
+		_exit(0);
+	}
+	/* parent */
+	assert(close(p[1]) == 0);
+	assert((sz = read(p[0], &report, sizeof(report))) >= 0);
+	assert(close(p[0]) == 0);
+	/* sz should be 0 if execvp() succeeded, sizeof(report) otherwise */
+	assert(sz == 0 || sz == sizeof(report));
+	assert(waitpid(pid, &status, 0) == pid);
+	if (statusp != NULL)
+		*statusp = status;
+	errno = report.err;
+	return (report.ret);
+}
+
+static int
+_fork_spawnp(const char *name, char *const args[], const char *search_path,
+    int *statusp)
+{
+	char *envp[2] = { NULL, NULL };
+	char *restore_path = NULL;
+	pid_t pid;
+	int ret, serrno, status;
+	bool need_restore = false;
+
+	if (search_path != NULL) {
+		need_restore = true;
+		restore_path = getenv("PATH");
+		if (restore_path != NULL) {
+			restore_path = strdup(restore_path);
+			assert(restore_path != NULL);
+		}
+
+		ret = setenv("PATH", search_path, 1);
+		assert(ret == 0);
+	} else {
+		search_path = getenv("PATH");
+		if (search_path == NULL)
+			search_path = _PATH_DEFPATH;
+	}
+
+	ret = asprintf(&envp[0], "PATH=%s", search_path);
+	assert(ret != -1);
+
+	ret = posix_spawnp(&pid, name, NULL, NULL, args, envp);
+	serrno = ret;
+	free(envp[0]);
+
+	if (ret == 0) {
+		assert(waitpid(pid, &status, 0) == pid);
+	} else {
+		ret = -1;
+		status = 0;
+	}
+
+	if (statusp != NULL)
+		*statusp = status;
+
+	if (need_restore) {
+		int sret = ret;
+
+		if (restore_path != NULL)
+			ret = setenv("PATH", restore_path, 1);
+		else
+			ret = unsetenv("PATH");
+
+		assert(ret == 0);
+		free(restore_path);
+		ret = sret;
+	}
+
+	errno = serrno;
+	return (ret);
+}
+
+/*
+ * Simple successful execvp() case using an absolute path and an empty
+ * search path.
+ */
+T_DECL(execvp_success_absolute, "Success case (absolute)")
+{
+	char *name = "/bin/echo";
+	char *args[] = { name, "Hello, world!", NULL };
+	int status;
+
+	T_EXPECT_POSIX_SUCCESS(_fork_execvp(name, args, "", &status),
+	    "Executing a program successfully");
+	if (T_RESULT == T_RESULT_PASS) {
+		T_EXPECT_TRUE(WIFEXITED(status), "Checking termination");
+		T_EXPECT_EQ(WEXITSTATUS(status), 0, "Checking exit code");
+	}
+}
+
+/*
+ * Simple successful posix_spawnp() case using an absolute path and an empty
+ * search path.
+ */
+T_DECL(spawnp_success_absolute, "Success case (absolute)")
+{
+	char *name = "/bin/echo";
+	char *args[] = { name, "Hello, world!", NULL };
+	int status;
+
+	T_EXPECT_POSIX_SUCCESS(_fork_spawnp(name, args, "", &status),
+	    "Executing a program successfully");
+	if (T_RESULT == T_RESULT_PASS) {
+		T_EXPECT_TRUE(WIFEXITED(status), "Checking termination");
+		T_EXPECT_EQ(WEXITSTATUS(status), 0, "Checking exit code");
+	}
+}
+
+/*
+ * Simple successful execvp() case using a relative path.
+ */
+T_DECL(execvp_success_relative, "Success case (relative)")
+{
+	char *name = "echo";
+	char *args[] = { name, "Hello, world!", NULL };
+	char *search_path = _PATH_DEFPATH;
+	int status;
+
+	T_EXPECT_POSIX_SUCCESS(_fork_execvp(name, args, search_path, &status),
+	    "Executing a program successfully");
+	if (T_RESULT == T_RESULT_PASS) {
+		T_EXPECT_TRUE(WIFEXITED(status), "Checking termination");
+		T_EXPECT_EQ(WEXITSTATUS(status), 0, "Checking exit code");
+	}
+}
+
+/*
+ * Simple successful posix_spawnp() case using a relative path.
+ */
+T_DECL(spawnp_success_relative, "Success case (relative)")
+{
+	char *name = "echo";
+	char *args[] = { name, "Hello, world!", NULL };
+	char *search_path = _PATH_DEFPATH;
+	int status;
+
+	T_EXPECT_POSIX_SUCCESS(_fork_spawnp(name, args, search_path, &status),
+	    "Executing a program successfully");
+	if (T_RESULT == T_RESULT_PASS) {
+		T_EXPECT_TRUE(WIFEXITED(status), "Checking termination");
+		T_EXPECT_EQ(WEXITSTATUS(status), 0, "Checking exit code");
+	}
+}
+
+/*
+ * Successful execvp() of a program which is a shell script lacking a
+ * shebang, thus relying on execvp()'s ENOEXEC fallback logic.
+ */
+T_DECL(execvp_success_ENOEXEC, "Script without shebang")
+{
+	const char *dir = dt_tmpdir();
+	char *name = "success_ENOEXEC";
+	char *args[] = { name, NULL };
+	char *script = "exec true";
+	int dd, pd;
+
+	T_SETUPBEGIN;
+	T_ASSERT_POSIX_SUCCESS(dd = open(dir, O_RDONLY),
+	    "Opening directory %s", dir);
+	T_ASSERT_POSIX_SUCCESS(pd = openat(dd, name, O_RDWR|O_TRUNC|O_CREAT),
+	    "Creating program %s in %s", name, dir);
+	T_ASSERT_POSIX_SUCCESS(fchmod(pd, 0755),
+	    "Changing program permissions");
+	T_ASSERT_POSIX_SUCCESS(write(pd, script, strlen(script)),
+	    "Writing code to program");
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program");
+	T_SETUPEND;
+
+	T_EXPECT_POSIX_SUCCESS(_fork_execvp(name, args, dir, NULL),
+	    "Executing a shell script that lacks a shebang");
+
+	T_SETUPBEGIN;
+	T_EXPECT_POSIX_SUCCESS(unlinkat(dd, name, 0),
+	    "Deleting program");
+	T_EXPECT_POSIX_SUCCESS(close(dd),
+	    "Closing temporary directory");
+	T_SETUPEND;
+}
+
+/*
+ * Attempt to invoke a program which is a shell script lacking a shebang,
+ * thus relying on execvp()'s ENOEXEC fallback logic, but with an empty
+ * argument list, which trips the bug described in rdar://107951804.
+ *
+ * In theory this is nondeterministic and the odds of the test passing
+ * even when the bug is present are good.  In practice we seem to reliably
+ * get an EFAULT.
+ */
+T_DECL(execvp_rdar_107951804, "Script without shebang with empty argv")
+{
+	const char *dir = dt_tmpdir();
+	char *name = "rdar_107951804";
+	char *args[] = { NULL };
+	char *script = "test $# -eq 0";
+	int dd, pd;
+	int status;
+
+	T_SETUPBEGIN;
+	T_ASSERT_POSIX_SUCCESS(dd = open(dir, O_RDONLY),
+	    "Opening directory %s", dir);
+	T_ASSERT_POSIX_SUCCESS(pd = openat(dd, name, O_RDWR|O_TRUNC|O_CREAT),
+	    "Creating program %s in %s", name, dir);
+	T_ASSERT_POSIX_SUCCESS(fchmod(pd, 0755),
+	    "Changing program permissions");
+	T_ASSERT_POSIX_SUCCESS(write(pd, script, strlen(script)),
+	    "Writing code to program");
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program");
+	T_SETUPEND;
+
+	T_EXPECT_POSIX_SUCCESS(_fork_execvp(name, args, dir, &status),
+	    "Executing a shell script that lacks a shebang with an empty argument list");
+	if (T_RESULT == T_RESULT_PASS) {
+		T_EXPECT_TRUE(WIFEXITED(status), "Checking termination");
+		T_EXPECT_EQ(WEXITSTATUS(status), 0, "Checking exit code");
+	}
+
+	T_SETUPBEGIN;
+	T_EXPECT_POSIX_SUCCESS(unlinkat(dd, name, 0),
+	    "Deleting program");
+	T_EXPECT_POSIX_SUCCESS(close(dd),
+	    "Closing temporary directory");
+	T_SETUPEND;
+}
+
+/*
+ * Attempt to execute a program which does not exist (absolute case).
+ */
+T_DECL(execvp_failure_ENOENT_absolute, "Failure case (ENOENT, absolute)")
+{
+	char *name = "/path/to/this!program?does#not@exist";
+	char *args[] = { name, NULL };
+
+	T_ASSERT_POSIX_FAILURE(_fork_execvp(name, args, "", NULL), ENOENT,
+	    "Trying to execute a program that does not exist");
+}
+
+/*
+ * Attempt to execute a program which does not exist (relative case).
+ */
+T_DECL(execvp_failure_ENOENT_relative, "Failure case (ENOENT, relative)")
+{
+	const char *dir = dt_tmpdir();
+	char *name = "this!program?does#not@exist";
+	char *args[] = { name, NULL };
+
+	T_ASSERT_POSIX_FAILURE(_fork_execvp(name, args, dir, NULL), ENOENT,
+	    "Trying to execute a program that does not exist");
+}
+
+/*
+ * Attempt to execute a program which is not executable.
+ */
+T_DECL(execvp_failure_EACCES, "Failure case (EACCES)")
+{
+	const char *dir = dt_tmpdir();
+	const char *template = "/usr/bin/true";
+	char *name = "program_EACCES";
+	char *args[] = { name, NULL };
+	int pd;
+
+	T_SETUPBEGIN;
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program(template, dir, name, 0444),
+	    "Creating program %s in %s", name, dir);
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program");
+	T_SETUPEND;
+
+	T_EXPECT_POSIX_FAILURE(_fork_execvp(name, args, dir, NULL), EACCES,
+	    "Trying to execute a program which is not executable");
+}
+
+/*
+ * Attempt to execute a program which is executable, but not by us.
+ */
+T_DECL(execvp_failure_EPERM, "Failure case (EPERM)", T_META_ASROOT(false),
+    T_META_CHECK_LEAKS(false))
+{
+	const char *dir = dt_tmpdir();
+	const char *template = "/usr/bin/true";
+	char *name = "program_EPERM";
+	char *args[] = { name, NULL };
+	int pd;
+
+	T_SETUPBEGIN;
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program(template, dir, name, 0445),
+	    "Creating program %s in %s", name, dir);
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program");
+	T_SETUPEND;
+
+	T_EXPECT_POSIX_FAILURE(_fork_execvp(name, args, dir, NULL), EACCES,
+	    "Trying to execute a program which is executable but not by us");
+}
+
+/*
+ * Attempt to execute a binary program while it is open for writing.
+ */
+T_DECL(execvp_failure_ETXTBSY, "Failure case (ETXTBSY)")
+{
+	const char *dir = dt_tmpdir();
+	const char *template = "/usr/bin/true";
+	char *name = "program_ETXTBSY";
+	char *args[] = { name, NULL };
+	int pd;
+
+	T_SETUPBEGIN;
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program(template, dir, name, 0555),
+	    "Creating program %s in %s", name, dir);
+	T_SETUPEND;
+
+	/*
+	 * This should fail, but doesn't.  May be filesystem-dependent.
+	 */
+	T_EXPECTFAIL;
+	T_EXPECT_POSIX_FAILURE(_fork_execvp(name, args, dir, NULL), ETXTBSY,
+	    "Trying to execute a program which is open for writing");
+
+	T_SETUPBEGIN;
+	T_EXPECT_POSIX_SUCCESS(close(pd),
+	    "Closing program");
+	T_SETUPEND;
+}
+
+/*
+ * Attempt to execute a program by absolute path which is too long.  We
+ * achieve this by creating a symlink that points to its containing
+ * directory so we can craft arbitrarily long paths to any file contained
+ * in that directory.
+ */
+T_DECL(execvp_failure_ENAMETOOLONG_absolute, "Failure case (ENAMETOOLONG, absolute)")
+{
+	const char *dir = dt_tmpdir();
+	const char *template = "/usr/bin/true";
+	char *linkname = "link_ENAMETOOLONG_absolute";
+	char *name = "program_ENAMETOOLONG_absolute";
+	char *args[] = { name, NULL };
+	char *full_path;
+	size_t name_max, path_max;
+	size_t len;
+	int dd, pd;
+	int ret;
+
+	T_SETUPBEGIN;
+	T_ASSERT_POSIX_SUCCESS(dd = open(dir, O_RDONLY),
+	    "Opening directory %s", dir);
+	(void)unlinkat(dd, linkname, 0);
+	T_ASSERT_POSIX_SUCCESS(symlinkat(".", dd, linkname),
+	    "Creating loopback symlink");
+	name_max = (size_t)fpathconf(dd, _PC_NAME_MAX);
+	T_LOG("NAME_MAX = %zu", name_max);
+	path_max = (size_t)fpathconf(dd, _PC_PATH_MAX);
+	T_LOG("PATH_MAX = %zu", path_max);
+	T_ASSERT_NOTNULL(full_path = malloc(path_max + name_max),
+	    "Allocating space for full path");
+	ret = snprintf(full_path, path_max + name_max, "%s", dir);
+	assert(ret >= 0);
+	len = (size_t)ret;
+	while (len + 1 + strlen(name) < path_max) {
+		ret = snprintf(full_path + len, path_max + name_max - len,
+		    "%s/", linkname);
+		assert(ret >= 0);
+		len += (size_t)ret;
+	}
+	ret = snprintf(full_path + len, path_max + name_max - len,
+	    "%s", name);
+	assert(ret >= 0);
+	len += (size_t)ret;
+	T_LOG("full path will be %s", full_path);
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program(template, dir, name, 0555),
+	    "Creating program %s in %s", name, dir);
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program");
+	T_EXPECT_POSIX_SUCCESS(close(dd),
+	    "Closing temporary directory");
+	T_SETUPEND;
+
+	T_EXPECT_POSIX_FAILURE(_fork_execvp(full_path, args, NULL, NULL), ENAMETOOLONG,
+	    "Trying to execute a program whose name is too long (absolute)");
+}
+
+/*
+ * Attempt to execute a program by relative path which is too long.  We
+ * achieve this by creating a symlink that points to its containing
+ * directory so we can craft arbitrarily long paths to any file contained
+ * in that directory.  We then craft a search path such that the requested
+ * program exists in the search path but the combined path is too long.
+ */
+T_DECL(execvp_failure_ENAMETOOLONG_relative, "Failure case (ENAMETOOLONG, relative)")
+{
+	const char *dir = dt_tmpdir();
+	const char *template = "/usr/bin/true";
+	char *linkname = "link_ENAMETOOLONG_relative";
+	char *name = "program_ENAMETOOLONG_relative";
+	char *args[] = { name, NULL };
+	char *relative_path;
+	size_t name_max, path_max;
+	size_t len;
+	int dd, pd;
+	int ret;
+
+	T_SETUPBEGIN;
+	T_ASSERT_POSIX_SUCCESS(dd = open(dir, O_RDONLY),
+	    "Opening directory %s", dir);
+	(void)unlinkat(dd, linkname, 0);
+	T_ASSERT_POSIX_SUCCESS(symlinkat(".", dd, linkname),
+	    "Creating loopback symlink");
+	name_max = (size_t)fpathconf(dd, _PC_NAME_MAX);
+	T_LOG("NAME_MAX = %zu", name_max);
+	path_max = (size_t)fpathconf(dd, _PC_PATH_MAX);
+	T_LOG("PATH_MAX = %zu", path_max);
+
+	/*
+	 * Add some extra space to make sure we thoroughly pass PATH_MAX,
+	 * regardless of the tmpdir length.
+	 */
+	path_max += strlen(linkname) + strlen(name) + 2;
+
+	T_ASSERT_NOTNULL(relative_path = malloc(path_max),
+	    "Allocating space for large relative path");
+	/* dt_tmpdir() won't normalize TMPDIR. */
+	ret = snprintf(relative_path, path_max, "%s%s", dir,
+	    dir[strlen(dir) - 1] == '/' ? "" : "/");
+	assert(ret >= 0);
+	len = (size_t)ret;
+	while (len + strlen(linkname) + 1 + strlen(name) < path_max) {
+		ret = snprintf(relative_path + len, path_max - len, "%s/",
+		    linkname);
+		assert(ret >= 0);
+		len += (size_t)ret;
+	}
+	snprintf(relative_path + len, path_max - len, "%s", name);
+	T_LOG("relative path will be %s", relative_path);
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program(template, dir, name, 0555),
+	    "Creating program %s in %s", name, dir);
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program");
+	T_EXPECT_POSIX_SUCCESS(close(dd),
+	    "Closing temporary directory");
+	T_SETUPEND;
+
+	T_EXPECT_POSIX_FAILURE(_fork_execvp(relative_path, args, NULL, NULL), ENAMETOOLONG,
+	    "Trying to execute a program whose name is too long (relative)");
+}
+
+static void
+setup_spawn_dirs(const char *dir)
+{
+	const char *template = "/usr/bin/true";
+	int dfd, pd, ret;
+
+	dfd = open(dir, O_DIRECTORY);
+	T_ASSERT_GE(dfd, 0, "Opening %s", dir);
+
+	ret = mkdirat(dfd, "dir1", 0755);
+	if (ret == -1 && errno != EEXIST)
+		T_ASSERT_POSIX_SUCCESS(ret, "Creating %s/dir1", dir);
+
+	ret = mkdirat(dfd, "dir2", 0755);
+	if (ret == -1 && errno != EEXIST)
+		T_ASSERT_POSIX_SUCCESS(ret, "Creating %s/dir2", dir);
+
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program_impl(template, dfd,
+	    "dir1/program1", 0755), "Creating program1 in %s/dir1", dir);
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program1");
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program_impl(template, dfd,
+	    "dir2/program2", 0755), "Creating program2 in %s/dir2", dir);
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program2");
+	T_ASSERT_POSIX_SUCCESS(pd = _copy_program_impl(template, dfd,
+	    "program3", 0755), "Creating program3 in %s", dir);
+	T_ASSERT_POSIX_SUCCESS(close(pd),
+	    "Closing program3");
+	T_ASSERT_POSIX_SUCCESS(close(dfd),
+	    "Closing tempdir dirfd");
+}
+
+/*
+ * Simple successful execvp() cases relying on PATH searching.
+ */
+T_DECL(execvp_success_searching, "Success case (searching)")
+{
+	const char *dir = dt_tmpdir();
+	char *search_path;
+	const char *name1 = "program1", *name2 = "program2";
+	const char *name3 = "program3";
+	char *args[2] = { NULL, NULL };
+	int ret;
+
+	T_SETUPBEGIN;
+	setup_spawn_dirs(dir);
+	T_SETUPEND;
+
+	ret = asprintf(&search_path, "%s/dir1:%s/dir2:", dir, dir);
+	T_ASSERT_GE(ret, 0, "Constructing search PATH");
+	T_LOG("search_path = %s", search_path);
+
+	args[0] = __DECONST(char *, name1);
+	T_EXPECT_POSIX_SUCCESS(_fork_execvp(name1, args, search_path, NULL),
+	    "Trying to execute a program in initial PATH");
+	args[0] = __DECONST(char *, name2);
+	T_EXPECT_POSIX_SUCCESS(_fork_execvp(name2, args, search_path, NULL),
+	    "Trying to execute a program in another part of PATH");
+
+	/* Implied CWD from component of PATH being empty */
+	args[0] = __DECONST(char *, name3);
+	T_EXPECT_POSIX_FAILURE(_fork_execvp(name3, args, search_path, NULL),
+	    ENOENT,
+	    "Trying to execute a program in empty part of PATH (wrong PWD)");
+	T_EXPECT_POSIX_SUCCESS(chdir(dir), "%s: chdir", dir);
+	T_EXPECT_POSIX_SUCCESS(_fork_execvp(name3, args, search_path, NULL),
+	    "Trying to execute a program in empty part of PATH (correct PWD)");
+
+	free(search_path);
+}
+
+/*
+ * Simple successful spawnp() cases relying on PATH searching.
+ */
+T_DECL(spawnp_success_searching, "Success case (searching)")
+{
+	const char *dir = dt_tmpdir();
+	char *search_path;
+	const char *name1 = "program1", *name2 = "program2";
+	const char *name3 = "program3";
+	char *args[2] = { NULL, NULL };
+	int ret;
+
+	T_SETUPBEGIN;
+	/* Ensure we're not in our tempdir. */
+	setup_spawn_dirs(dir);
+	T_SETUPEND;
+
+	ret = asprintf(&search_path, "%s/dir1:%s/dir2:", dir, dir);
+	T_ASSERT_GE(ret, 0, "Constructing search PATH");
+	T_LOG("search_path = %s", search_path);
+
+	args[0] = __DECONST(char *, name1);
+	T_EXPECT_POSIX_SUCCESS(_fork_spawnp(name1, args, search_path, NULL),
+	    "Trying to execute a program in initial PATH");
+	args[0] = __DECONST(char *, name2);
+	T_EXPECT_POSIX_SUCCESS(_fork_spawnp(name2, args, search_path, NULL),
+	    "Trying to execute a program in another part of PATH");
+
+	/* Implied CWD from component of PATH being empty */
+	args[0] = __DECONST(char *, name3);
+	T_EXPECT_POSIX_FAILURE(_fork_spawnp(name3, args, search_path, NULL),
+	    ENOENT,
+	    "Trying to execute a program in empty part of PATH (wrong PWD)");
+	T_EXPECT_POSIX_SUCCESS(chdir(dir), "%s: chdir", dir);
+	T_EXPECT_POSIX_SUCCESS(_fork_spawnp(name3, args, search_path, NULL),
+	    "Trying to execute a program in empty part of PATH (correct PWD)");
+
+	free(search_path);
+}