[NaCl SDK] nacl_io: Fix FuseFs.{read,write}

native_client_sdk/src/tests/nacl_io_test/fuse_fs_test.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <fcntl.h>
 
 #include <gtest/gtest.h>
 
 #include <string>
 #include <vector>
@@ skipping 204 matching lines @@
 }  // namespace
 
 TEST_F(FuseFsTest, OpenAndRead) {
   ScopedNode node;
   ASSERT_EQ(0, fs_.Open(Path("/hello"), O_RDONLY, &node));
 
   char buffer[15] = {0};
   int bytes_read = 0;
   HandleAttr attr;
   ASSERT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
-  // FUSE always fills the buffer (padding with \0) unless in direct_io mode.
-  ASSERT_EQ(sizeof(buffer), bytes_read);
+  ASSERT_EQ(strlen(hello_world), bytes_read);
   ASSERT_STREQ(hello_world, buffer);
+
+  // Try to read past the end of the file.
+  attr.offs = strlen(hello_world) - 7;
+  ASSERT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
+  ASSERT_EQ(7, bytes_read);
+  ASSERT_STREQ("World!\n", buffer);
 }
 
 TEST_F(FuseFsTest, CreateAndWrite) {
   ScopedNode node;
   ASSERT_EQ(0, fs_.Open(Path("/foobar"), O_RDWR | O_CREAT, &node));
 
   HandleAttr attr;
   const char message[] = "Something interesting";
   int bytes_written;
   ASSERT_EQ(0, node->Write(attr, &message[0], strlen(message), &bytes_written));
   ASSERT_EQ(bytes_written, strlen(message));
 
   // Now try to read the data back.
   char buffer[40] = {0};
   int bytes_read = 0;
   ASSERT_EQ(0, node->Read(attr, &buffer[0], sizeof(buffer), &bytes_read));
-  // FUSE always fills the buffer (padding with \0) unless in direct_io mode.
-  ASSERT_EQ(sizeof(buffer), bytes_read);
+  ASSERT_EQ(strlen(message), bytes_read);
   ASSERT_STREQ(message, buffer);
 }
 
 TEST_F(FuseFsTest, GetStat) {
   struct stat statbuf;
   ScopedNode node;
 
   ASSERT_EQ(0, fs_.Open(Path("/hello"), O_RDONLY, &node));
   EXPECT_EQ(0, node->GetStat(&statbuf));
   EXPECT_EQ(S_IFREG, statbuf.st_mode & S_IFMT);
@@ skipping 86 matching lines @@
   ASSERT_EQ(sizeof(hello_world),
             ki_write(fd, hello_world, sizeof(hello_world)));
   EXPECT_EQ(0, ki_close(fd));
 
   // Then read it back in.
   fd = ki_open("/hello", O_RDONLY);
   ASSERT_GT(fd, -1);
 
   char buffer[30];
   memset(buffer, 0, sizeof(buffer));
-  ASSERT_EQ(sizeof(buffer), ki_read(fd, buffer, sizeof(buffer)));
+  ASSERT_EQ(sizeof(hello_world), ki_read(fd, buffer, sizeof(buffer)));
   EXPECT_STREQ(hello_world, buffer);
   EXPECT_EQ(0, ki_close(fd));
 }