1 files changed, 80 insertions, 0 deletions
diff --git a/tests/test_dir_rewind.c b/tests/test_dir_rewind.c
new file mode 100644
index 0000000..d4050f9
--- /dev/null
+++ b/tests/test_dir_rewind.c
@@ -0,0 +1,80 @@
+// Tests that opening the current directory, reading its entries
+// rewinding and reading its entries again gives the same entries both times.
+//
+// https://github.com/mpartel/bindfs/issues/41
+
+#ifdef __linux__
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#define BUF_SIZE 4096
+
+int main()
+{
+    int fd = open(".", O_RDONLY | O_DIRECTORY);
+    if (fd == -1) {
+        perror("failed to open '.'");
+        return 1;
+    }
+
+    char buf1[BUF_SIZE];
+    char buf2[BUF_SIZE];
+    memset(buf1, 0, BUF_SIZE);
+    memset(buf2, 0, BUF_SIZE);
+
+    int amt_read1 = syscall(SYS_getdents, fd, buf1, BUF_SIZE);
+    if (amt_read1 <= 0) {
+        fprintf(stderr, "amt_read1=%d\n", amt_read1);
+        close(fd);
+        return 1;
+    }
+
+    off_t seek_res = lseek(fd, 0, SEEK_SET);
+    if (seek_res == (off_t)-1) {
+        perror("failed to lseek to 0");
+        close(fd);
+        return 1;
+    }
+
+    int amt_read2 = syscall(SYS_getdents, fd, buf2, BUF_SIZE);
+    if (amt_read2 <= 0) {
+        fprintf(stderr, "amt_read2=%d\n", amt_read2);
+        close(fd);
+        return 1;
+    }
+
+    if (amt_read1 != amt_read2) {
+        fprintf(stderr,
+                "First read gave %d bytes, second read gave %d bytes.\n",
+                amt_read1, amt_read2);
+        close(fd);
+        return 1;
+    }
+    if (memcmp(buf1, buf2, BUF_SIZE) != 0) {
+        fprintf(stderr, "First and second read results differ.\n");
+        close(fd);
+        return 1;
+    }
+
+    close(fd);
+    return 0;
+}
+
+#else  // #ifdef __linux__
+
+int main()
+{
+    printf("This test (probably) only compiles on Linux.\n");
+    printf("Skipping by just returning successfully.\n");
+    return 0;
+}
+
+#endif  // #ifdef __linux__