String cleanup in sync code

chrome/browser/sync/util/path_helpers_win.cc

+// Copyright (c) 2009 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 "chrome/browser/sync/util/path_helpers.h"
+
+#include <Shlwapi.h>
+#include <stdlib.h>
+
+#include "base/logging.h"
+#include "base/port.h"
+#include "build/build_config.h"
+#include "chrome/browser/sync/syncable/syncable.h"
+
+#ifndef OS_WIN
+#error Compile this file on Windows only.
+#endif
+
+using std::string;
+
+namespace {
+const PathString kWindowsIllegalBaseFilenames[] = {
+    "CON", "PRN", "AUX", "NUL", "COM1", "COM2",
+    "COM3", "COM4", "COM5", "COM6", "COM7",
+    "COM8", "COM9", "LPT1", "LPT2", "LPT3",
+    "LPT4", "LPT5", "LPT6", "LPT7", "LPT8",
+    "LPT9" };
+}
+
+// See: http://msdn.microsoft.com/library/default.asp?url=/library/
+// en-us/fileio/fs/naming_a_file.asp
+// note that * and ? are not listed on the page as illegal characters,
+// but they are.
+PathString MakePathComponentOSLegal(const PathString& component) {
+  CHECK(!component.empty());
+  PathString mutable_component = component;
+
+  // Remove illegal characters.
+  for (PathString::iterator i = mutable_component.begin();
+       i != mutable_component.end();) {
+    if ((PathString::npos != PathString("<>:\"/\\|*?").find(*i)) ||
+        ((static_cast<unsigned short>(*i) >= 0) &&
+         (static_cast<unsigned short>(*i) <= 31))) {
+      mutable_component.erase(i);
+    } else {
+      ++i;
+    }
+  }
+
+  // Remove trailing spaces or periods.
+  while (mutable_component.size() &&
+         ((mutable_component.at(mutable_component.size() - 1) == ' ') ||
+          (mutable_component.at(mutable_component.size() - 1) == '.')))
+    mutable_component.resize(mutable_component.size() - 1, ' ');
+
+  // Remove a bunch of forbidden names. windows only seems to mind if
+  // a forbidden name matches our name exactly (e.g. "prn") or if the name is
+  // the forbidden name, followed by a dot, followed by anything
+  // (e.g., "prn.anything.foo.bar")
+
+  // From this point out, we break mutable_component into two strings, and use
+  // them this way: we save anything after and including the first dot (usually
+  // the extension) and only mess with stuff before the first dot.
+  PathString::size_type first_dot = mutable_component.find_first_of('.');
+  if (PathString::npos == first_dot)
+    first_dot = mutable_component.size();
+  PathString sub = mutable_component.substr(0, first_dot);
+  PathString postsub = mutable_component.substr(first_dot);
+  CHECK(sub + postsub == mutable_component);
+  for (int i = 0; i < ARRAYSIZE(kWindowsIllegalBaseFilenames); i++) {
+    // ComparePathNames(a, b) == 0 -> same
+    if (syncable::ComparePathNames(kWindowsIllegalBaseFilenames[i], sub) == 0) {
+      sub.append("~1");
+      break;
+    }
+  }
+  if (("" == sub) && ("" == postsub)) {
+    sub = "~1";
+  }
+
+  // Return the new name, only if it differs from the original.
+  if ((sub + postsub) == component)
+    return "";
+  return (sub + postsub);
+}