Implement FilePath::Contains()

base/file_path.cc

 // Copyright (c) 2008 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_path.h"
+#include "base/file_util.h"
 #include "base/logging.h"
 
 // These includes are just for the *Hack functions, and should be removed
 // when those functions are removed.
 #include "base/string_piece.h"
+#include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 
 #if defined(FILE_PATH_USES_WIN_SEPARATORS)
 const FilePath::CharType FilePath::kSeparators[] = FILE_PATH_LITERAL("\\/");
 #else  // FILE_PATH_USES_WIN_SEPARATORS
 const FilePath::CharType FilePath::kSeparators[] = FILE_PATH_LITERAL("/");
 #endif  // FILE_PATH_USES_WIN_SEPARATORS
 
 const FilePath::CharType FilePath::kCurrentDirectory[] = FILE_PATH_LITERAL(".");
 const FilePath::CharType FilePath::kParentDirectory[] = FILE_PATH_LITERAL("..");
@@ skipping 150 matching lines @@
 }
 
 FilePath FilePath::Append(const FilePath& component) const {
   return Append(component.value());
 }
 
 bool FilePath::IsAbsolute() const {
   return IsPathAbsolute(path_);
 }
 
+bool FilePath::Contains(const FilePath &other) const {
+  FilePath parent = FilePath(*this);
+  FilePath child = FilePath(other);
+
+  if (!file_util::AbsolutePath(&parent) || !file_util::AbsolutePath(&child))
+    return false;
+
+#if defined(OS_WIN)
+  // file_util::AbsolutePath() does not flatten case on Windows, so we must do
+  // a case-insensitive compare.
+  if (!StartsWith(child.value(), parent.value(), false))
+#else
+  if (!StartsWithASCII(child.value(), parent.value(), true))
+#endif
+    return false;
+
+  // file_util::AbsolutePath() normalizes '/' to '\', so we only need to check
+  // kSeparators[0].
+  if (child.value().length() <= parent.value().length() ||
+      child.value()[parent.value().length()] != kSeparators[0])
+    return false;
+
+  return true;
+}
+
 #if defined(OS_POSIX)
 // See file_path.h for a discussion of the encoding of paths on POSIX
 // platforms.  These *Hack() functions are not quite correct, but they're
 // only temporary while we fix the remainder of the code.
 // Remember to remove the #includes at the top when you remove these.
 
 // static
 FilePath FilePath::FromWStringHack(const std::wstring& wstring) {
   return FilePath(base::SysWideToNativeMB(wstring));
 }
@@ skipping 31 matching lines @@
        --pos) {
     // If the string only has two separators and they're at the beginning,
     // don't strip them, unless the string began with more than two separators.
     if (pos != start + 1 || last_stripped == start + 2 ||
         !IsSeparator(path_[start - 1])) {
       path_.resize(pos - 1);
       last_stripped = pos;
     }
   }
 }