Make improvements

- Introduce ualarm() function
- Make rename() report EISEMPTY on Windows
- Always raise EINVAL upon open(O_RDONLY|O_TRUNC)
- Add macro so ./configure will detect SOCK_CLOEXEC
- Fix O_TRUNC without O_CREAT not working on Windows
- Let fcntl(F_SETFL) change O_APPEND status on Windows
- Make sure pwrite() / pread() report ESPIPE on sockets
- Raise ESPIPE on Windows when pwrite() is used on pipe
- Properly compute O_APPEND CreateFile() flags on Windows
- Don't require O_DIRECTORY to open directories on Windows
- Fix more instances of Windows reporting EISDIR and ENOTDIR
- Normalize EFTYPE and EMLINK to ELOOP on NetBSD and FreeBSD
- Make unlink() / rmdir() work on read-only files on Windows
- Validate UTF-8 on Windows paths to fix bug with overlong NUL
- Always print signal name to stderr when crashing due to SIG_DFL
- Fix Windows bug where denormalized paths >260 chars didn't work
- Block signals on BSDs when thread exits before trashing its own stack

test/libc/calls/renameat_test.c

@@ -17,7 +17,9 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
+#include "libc/dce.h"
 #include "libc/errno.h"
+#include "libc/runtime/runtime.h"
 #include "libc/sysv/consts/at.h"
 #include "libc/testlib/testlib.h"
 #include "libc/x/x.h"
@@ -42,18 +44,76 @@ TEST(renameat, enotdir) {
   // EXPECT_SYS(ENOTDIR, -1, rename("zoo", "yo/there"));
 }
 
+TEST(rename, eisdir) {
+  // new is a directory but old is not a directory
+  ASSERT_SYS(0, 0, mkdir("foo", 0755));
+  ASSERT_SYS(0, 0, touch("foo/bar", 0644));
+  ASSERT_SYS(0, 0, touch("lol", 0644));
+  ASSERT_SYS(EISDIR, -1, rename("lol", "foo"));
+}
+
+TEST(rename, enotdir) {
+  // old is a directory but new is not a directory
+  ASSERT_SYS(0, 0, mkdir("lol", 0755));
+  ASSERT_SYS(0, 0, touch("foo", 0644));
+  ASSERT_SYS(ENOTDIR, -1, rename("lol", "foo"));
+}
+
+TEST(rename, eisdir_again) {
+  // old is a directory but new is not a directory
+  ASSERT_SYS(0, 0, touch("foo", 0644));
+  ASSERT_SYS(0, 0, touch("bar", 0644));
+  ASSERT_SYS(ENOTDIR, -1, rename("foo/", "bar"));
+  ASSERT_SYS(ENOTDIR, -1, rename("foo", "bar/"));
+}
+
+TEST(rename, moveDirectoryOverDirectory_replacesOldDirectory) {
+  ASSERT_SYS(0, 0, mkdir("foo//", 0755));
+  ASSERT_SYS(0, 0, mkdir("lol", 0755));
+  ASSERT_SYS(0, 0, rename("lol", "foo"));
+  ASSERT_TRUE(fileexists("foo"));
+  ASSERT_FALSE(fileexists("lol"));
+}
+
+TEST(rename, enotempty) {
+  // POSIX specifies EEXIST or ENOTEMPTY when new path is non-empty dir.
+  // Old version of Linux (e.g. RHEL7) return EEXIST.
+  // Everything else returns ENOTEMPTY.
+  int rc;
+  ASSERT_SYS(0, 0, mkdir("foo", 0755));
+  ASSERT_SYS(0, 0, touch("foo/bar", 0644));
+  ASSERT_SYS(0, 0, mkdir("lol", 0755));
+  ASSERT_EQ(-1, (rc = rename("lol", "foo")));
+  ASSERT_TRUE(errno == ENOTEMPTY || errno == EEXIST);
+  errno = 0;
+}
+
+TEST(rename, moveIntoNonWritableDirectory_raisesEacces) {
+  // old versions of linux allow this
+  // new versions of linux report exdev?!
+  if (IsLinux()) return;
+  // netbsd and openbsd allow this
+  if (IsNetbsd() || IsOpenbsd()) return;
+  // windows doesn't really have permissions
+  if (IsWindows()) return;
+  // posix specifies this behavior
+  ASSERT_SYS(0, 0, mkdir("foo", 0111));
+  ASSERT_SYS(0, 0, touch("lol", 0644));
+  ASSERT_SYS(EACCES, -1, rename("lol", "foo/bar"));
+}
+
 TEST(renameat, testNull_returnsEfault) {
   ASSERT_SYS(0, 0, close(creat("hello", 0644)));
-  EXPECT_SYS(EFAULT, -1, renameat(AT_FDCWD, 0, AT_FDCWD, 0));
-  EXPECT_SYS(EFAULT, -1, renameat(AT_FDCWD, 0, AT_FDCWD, "hello"));
-  EXPECT_SYS(EFAULT, -1, renameat(AT_FDCWD, "hello", AT_FDCWD, 0));
+  ASSERT_SYS(EFAULT, -1, renameat(AT_FDCWD, 0, AT_FDCWD, 0));
+  ASSERT_SYS(EFAULT, -1, renameat(AT_FDCWD, 0, AT_FDCWD, "hello"));
+  ASSERT_SYS(EFAULT, -1, renameat(AT_FDCWD, "hello", AT_FDCWD, 0));
 }
 
 TEST(renameat, test) {
   ASSERT_SYS(0, 0, close(creat("first", 0644)));
-  EXPECT_TRUE(fileexists("first"));
-  EXPECT_TRUE(!fileexists("second"));
-  EXPECT_SYS(0, 0, renameat(AT_FDCWD, "first", AT_FDCWD, "second"));
-  EXPECT_TRUE(!fileexists("first"));
-  EXPECT_TRUE(fileexists("second"));
+  ASSERT_TRUE(fileexists("first"));
+  ASSERT_TRUE(!fileexists("second"));
+  ASSERT_SYS(0, 0, renameat(AT_FDCWD, "first", AT_FDCWD, "second"));
+  ASSERT_TRUE(!fileexists("first"));
+  ASSERT_TRUE(fileexists("second"));
 }