Give the extension unpacker process a junction/symlink free path to the unpack directory.

base/file_util_posix.cc

 // Copyright (c) 2010 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 "base/file_util.h"
 
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fnmatch.h>
@@ skipping 26 matching lines @@
 #include "base/logging.h"
 #include "base/scoped_ptr.h"
 #include "base/singleton.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 
 namespace file_util {
 
+namespace {
+
+// Helper for NormalizeFilePath(), defined below.
+bool RealPath(const FilePath& path, FilePath* real_path) {
+  FilePath::CharType buf[PATH_MAX];
+  if (!realpath(path.value().c_str(), buf))
+    return false;
+
+  *real_path = FilePath(buf);
+  return true;
+}
+
+}  // namespace
+
 #if defined(OS_OPENBSD) || defined(OS_FREEBSD) || \
     (defined(OS_MACOSX) && \
      MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5)
 typedef struct stat stat_wrapper_t;
 static int CallStat(const char *path, stat_wrapper_t *sb) {
   return stat(path, sb);
 }
 #else
 typedef struct stat64 stat_wrapper_t;
 static int CallStat(const char *path, stat_wrapper_t *sb) {
@@ skipping 662 matching lines @@
   data_ = NULL;
   length_ = 0;
   file_ = base::kInvalidPlatformFileValue;
 }
 
 bool HasFileBeenModifiedSince(const FileEnumerator::FindInfo& find_info,
                               const base::Time& cutoff_time) {
   return find_info.stat.st_mtime >= cutoff_time.ToTimeT();
 }
 
-bool RealPath(const FilePath& path, FilePath* real_path) {
-  FilePath::CharType buf[PATH_MAX];
-  if (!realpath(path.value().c_str(), buf))
+bool NormalizeFilePath(const FilePath& path, FilePath* normalized_path) {
+  FilePath real_path_result;
+  if (!RealPath(path, &real_path_result))
     return false;
 
-  *real_path = FilePath(buf);
+  // To be consistant with windows, fail if |real_path_result| is a
+  // directory.
+  stat_wrapper_t file_info;
+  if (CallStat(real_path_result.value().c_str(), &file_info) != 0 ||
+      S_ISDIR(file_info.st_mode))
+    return false;
+
+  *normalized_path = real_path_result;
   return true;
 }
 
 #if !defined(OS_MACOSX)
 bool GetTempDir(FilePath* path) {
   const char* tmp = getenv("TMPDIR");
   if (tmp)
     *path = FilePath(tmp);
   else
     *path = FilePath("/tmp");
@@ skipping 63 matching lines @@
   if (HANDLE_EINTR(close(infile)) < 0)
     result = false;
   if (HANDLE_EINTR(close(outfile)) < 0)
     result = false;
 
   return result;
 }
 #endif  // defined(OS_MACOSX)
 
 } // namespace file_util