2 files changed, 112 insertions, 2 deletions
diff --git a/tests/stdio/test_fgetc_ungetc.c b/tests/stdio/test_fgetc_ungetc.c
index c69a3d1a..0eea4007 100644
--- a/tests/stdio/test_fgetc_ungetc.c
+++ b/tests/stdio/test_fgetc_ungetc.c
@@ -1,5 +1,6 @@
 #include <assert.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -47,7 +48,9 @@ void test() {
   ungetc('a', file);
   err = fgetc(file);
   assert(err == (int)'a');
-  fread(buffer, sizeof(char), sizeof(buffer), file);
+  int r = fread(buffer, sizeof(char), sizeof(buffer), file);
+  assert(r == 3);
+  buffer[3] = 0;
   assert(!strcmp(buffer, "bcd"));
 
   // rewind and fseek should reset anything that's been
@@ -84,4 +87,4 @@ int main() {
   setup();
   test();
   return EXIT_SUCCESS;
-}
-\ No newline at end of file
+}
diff --git a/tests/stdio/test_rename.c b/tests/stdio/test_rename.c
new file mode 100644
index 00000000..20ffb513
--- /dev/null
+++ b/tests/stdio/test_rename.c
@@ -0,0 +1,107 @@
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+void create_file(const char *path, const char *buffer, int mode) {
+  int fd = open(path, O_WRONLY | O_CREAT | O_EXCL, mode);
+  assert(fd >= 0);
+
+  int err = write(fd, buffer, sizeof(char) * strlen(buffer));
+  assert(err ==  (sizeof(char) * strlen(buffer)));
+
+  close(fd);
+}
+
+void setup() {
+  create_file("file", "abcdef", 0777);
+  mkdir("dir", 0777);
+  create_file("dir/file", "abcdef", 0777);
+  mkdir("dir/subdir", 0777);
+  mkdir("dir-readonly", 0555);
+  mkdir("dir-nonempty", 0777);
+  create_file("dir-nonempty/file", "abcdef", 0777);
+}
+
+void cleanup() {
+  // we're hulk-smashing and removing original + renamed files to
+  // make sure we get it all regardless of anything failing
+  unlink("file");
+  unlink("dir/file");
+  unlink("dir/file1");
+  unlink("dir/file2");
+  rmdir("dir/subdir");
+  rmdir("dir/subdir1");
+  rmdir("dir/subdir2");
+  rmdir("dir");
+  rmdir("dir-readonly");
+  unlink("dir-nonempty/file");
+  rmdir("dir-nonempty");
+}
+
+void test() {
+  int err;
+
+  // can't rename something that doesn't exist
+  err = rename("noexist", "dir");
+  assert(err == -1);
+  assert(errno == ENOENT);
+
+  // can't overwrite a folder with a file
+  err = rename("file", "dir");
+  assert(err == -1);
+  assert(errno == EISDIR);
+
+  // can't overwrite a file with a folder
+  err = rename("dir", "file");
+  assert(err == -1);
+  assert(errno == ENOTDIR);
+
+  // can't overwrite a non-empty folder
+  err = rename("dir", "dir-nonempty");
+  assert(err == -1);
+  assert(errno == ENOTEMPTY);
+
+  // can't create anything in a read-only directory
+  err = rename("dir", "dir-readonly/dir");
+  assert(err == -1);
+  assert(errno == EACCES);
+
+  // source should not be ancestor of target
+  err = rename("dir", "dir/somename");
+  assert(err == -1);
+  assert(errno == EINVAL);
+
+  // target should not be an ancestor of source
+  err = rename("dir/subdir", "dir");
+  assert(err == -1);
+  assert(errno == ENOTEMPTY);
+
+  // do some valid renaming
+  err = rename("dir/file", "dir/file1");
+  assert(!err);
+  err = rename("dir/file1", "dir/file2");
+  assert(!err);
+  err = access("dir/file2", F_OK);
+  assert(!err);
+  err = rename("dir/subdir", "dir/subdir1");
+  assert(!err);
+  err = rename("dir/subdir1", "dir/subdir2");
+  assert(!err);
+  err = access("dir/subdir2", F_OK);
+  assert(!err);
+
+  puts("success");
+}
+
+int main() {
+  atexit(cleanup);
+  signal(SIGABRT, cleanup);
+  setup();
+  test();
+  return EXIT_SUCCESS;
+}
+\ No newline at end of file