added reading beyond file length testcase

src/test/test_hydrogen.c

@@ -738,6 +738,48 @@ TEST(read_chunk_huge)
 TEST_END(read_chunk_huge)
 
 
+TEST(read_beyond)
+{
+  char *name = "file";
+  spiffs_file fd;
+  s32_t res;
+  u32_t size = SPIFFS_DATA_PAGE_SIZE(FS)*2;
+
+  u8_t *buf = malloc(size);
+  memrand(buf, size);
+
+  res = test_create_file(name);
+  CHECK(res >= 0);
+  fd = SPIFFS_open(FS, name, SPIFFS_APPEND | SPIFFS_RDWR, 0);
+  CHECK(fd >= 0);
+  res = SPIFFS_write(FS, fd, buf, size);
+  CHECK(res >= 0);
+
+  spiffs_stat stat;
+  res = SPIFFS_fstat(FS, fd, &stat);
+  CHECK(res >= 0);
+  CHECK(stat.size == size);
+
+  SPIFFS_close(FS, fd);
+
+  fd = SPIFFS_open(FS, name, SPIFFS_RDONLY, 0);
+  CHECK(fd >= 0);
+
+  u8_t *rbuf = malloc(size+10);
+  res = SPIFFS_read(FS, fd, rbuf, size+10);
+
+  SPIFFS_close(FS, fd);
+
+  free(rbuf);
+  free(buf);
+
+  TEST_CHECK(res == size);
+
+  return TEST_RES_OK;
+}
+TEST_END(read_beyond)
+
+
 TEST(bad_index_1) {
   int size = SPIFFS_DATA_PAGE_SIZE(FS)*3;
   int res = test_create_and_write_file("file", size, size);