fs, pipe: no trailing terminator in exact sized buffers

uv_fs_poll_getpath, uv_pipe_getsockname, uv_fs_event_getpath used
to return the trailing null terminator, even though the functions
returned the size.

Fixes: https://github.com/libuv/libuv/issues/155
PR-URL: https://github.com/libuv/libuv/pull/159
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>

docs/src/fs_event.rst

@@ -102,4 +102,7 @@ API
     is not big enough UV_ENOBUFS will be returned and len will be set to the
     required size.
 
+    .. versionchanged:: 1.3.0 the returned length no longer includes the terminating null byte,
+                        and the buffer is not null terminated.
+
 .. seealso:: The :c:type:`uv_handle_t` API functions also apply.

docs/src/fs_poll.rst

@@ -66,4 +66,7 @@ API
     is not big enough UV_ENOBUFS will be returned and len will be set to the
     required size.
 
+    .. versionchanged:: 1.3.0 the returned length no longer includes the terminating null byte,
+                        and the buffer is not null terminated.
+
 .. seealso:: The :c:type:`uv_handle_t` API functions also apply.

docs/src/pipe.rst

@@ -65,6 +65,9 @@ API
     output. If the buffer is not big enough ``UV_ENOBUFS`` will be returned and
     len will contain the required size.
 
+    .. versionchanged:: 1.3.0 the returned length no longer includes the terminating null byte,
+                        and the buffer is not null terminated.
+
 .. c:function:: void uv_pipe_pending_instances(uv_pipe_t* handle, int count)
 
     Set the number of pending pipe instance handles when the pipe server is

src/fs-poll.c

@@ -137,7 +137,7 @@ int uv_fs_poll_getpath(uv_fs_poll_t* handle, char* buf, size_t* len) {
   ctx = handle->poll_ctx;
   assert(ctx != NULL);
 
-  required_len = strlen(ctx->path) + 1;
+  required_len = strlen(ctx->path);
   if (required_len > *len) {
     *len = required_len;
     return UV_ENOBUFS;

src/unix/pipe.c

@@ -223,7 +223,7 @@ int uv_pipe_getsockname(const uv_pipe_t* handle, char* buf, size_t* len) {
     /* Linux abstract namespace */
     addrlen -= offsetof(struct sockaddr_un, sun_path);
   else
-    addrlen = strlen(sa.sun_path) + 1;
+    addrlen = strlen(sa.sun_path);
 
 
   if (addrlen > *len) {

src/uv-common.c

@@ -367,7 +367,7 @@ int uv_fs_event_getpath(uv_fs_event_t* handle, char* buf, size_t* len) {
     return UV_EINVAL;
   }
 
-  required_len = strlen(handle->path) + 1;
+  required_len = strlen(handle->path);
   if (required_len > *len) {
     *len = required_len;
     return UV_ENOBUFS;

src/win/pipe.c

@@ -1987,9 +1987,9 @@ int uv_pipe_getsockname(const uv_pipe_t* handle, char* buf, size_t* len) {
     *len = 0;
     err = uv_translate_sys_error(GetLastError());
     goto error;
-  } else if (pipe_prefix_len + addrlen + 1 > *len) {
+  } else if (pipe_prefix_len + addrlen > *len) {
-    /* "\\\\.\\pipe" + name + '\0' */
+    /* "\\\\.\\pipe" + name */
-    *len = pipe_prefix_len + addrlen + 1;
+    *len = pipe_prefix_len + addrlen;
     err = UV_ENOBUFS;
     goto error;
   }
@@ -2010,7 +2010,6 @@ int uv_pipe_getsockname(const uv_pipe_t* handle, char* buf, size_t* len) {
   }
 
   addrlen += pipe_prefix_len;
-  buf[addrlen++] = '\0';
   *len = addrlen;
 
   err = 0;

test/test-fs-event.c

@@ -642,6 +642,7 @@ TEST_IMPL(fs_event_getpath) {
   len = sizeof buf;
   r = uv_fs_event_getpath(&fs_event, buf, &len);
   ASSERT(r == 0);
+  ASSERT(buf[len - 1] != 0);
   ASSERT(memcmp(buf, "watch_dir", len) == 0);
   r = uv_fs_event_stop(&fs_event);
   ASSERT(r == 0);

test/test-fs-poll.c

@@ -172,6 +172,7 @@ TEST_IMPL(fs_poll_getpath) {
   ASSERT(0 == uv_fs_poll_start(&poll_handle, poll_cb_fail, FIXTURE, 100));
   len = sizeof buf;
   ASSERT(0 == uv_fs_poll_getpath(&poll_handle, buf, &len));
+  ASSERT(buf[len - 1] != 0);
   ASSERT(0 == memcmp(buf, FIXTURE, len));
 
   uv_close((uv_handle_t*) &poll_handle, close_cb);

test/test-pipe-getsockname.c

@@ -60,6 +60,7 @@ TEST_IMPL(pipe_getsockname) {
   len = sizeof buf;
   r = uv_pipe_getsockname(&server, buf, &len);
   ASSERT(r == 0);
+  ASSERT(buf[len - 1] != 0);
 
   ASSERT(memcmp(buf, TEST_PIPENAME, len) == 0);
 
@@ -149,6 +150,7 @@ TEST_IMPL(pipe_getsockname_blocking) {
   len1 = sizeof buf1;
   r = uv_pipe_getsockname(&reader, buf1, &len1);
   ASSERT(r == 0);
+  ASSERT(buf1[len1 - 1] != 0);
 
   r = uv_read_start((uv_stream_t*)&reader, NULL, NULL);
   ASSERT(r == 0);
@@ -157,6 +159,7 @@ TEST_IMPL(pipe_getsockname_blocking) {
   len2 = sizeof buf2;
   r = uv_pipe_getsockname(&reader, buf2, &len2);
   ASSERT(r == 0);
+  ASSERT(buf2[len2 - 1] != 0);
 
   r = uv_read_stop((uv_stream_t*)&reader);
   ASSERT(r == 0);