Do not allow multiline input when naming bookmarks/folders on Mac

chrome/browser/ui/cocoa/bookmarks/bookmark_name_folder_controller.mm

 // Copyright (c) 2011 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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_name_folder_controller.h"
 
 #include "base/mac/mac_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/cocoa/bookmarks/bookmark_model_observer_for_cocoa.h"
@@ skipping 70 matching lines @@
       modalDelegate:self
      didEndSelector:@selector(didEndSheet:returnCode:contextInfo:)
         contextInfo:nil];
 }
 
 - (IBAction)cancel:(id)sender {
   [NSApp endSheet:[self window]];
 }
 
 - (IBAction)ok:(id)sender {
-  NSString* name = [nameField_ stringValue];
   BookmarkModel* model = profile_->GetBookmarkModel();
+  NSMutableString* name =
+      [[NSMutableString alloc] initWithString:[nameField_ stringValue]];
+
+  // Replace occurrences of multiple newlines with single newlines.
+  while (NSNotFound != [name rangeOfString:@"\n\n"].location) {
+    [name replaceOccurrencesOfString:@"\n\n"
+                          withString:@"\n"
+                             options:0
+                               range:NSMakeRange(0, [name length])];
+  }
+
+  // Replace single newlines with single spaces.
+  [name replaceOccurrencesOfString:@"\n"
+                        withString:@" "
+                           options:0
+                             range:NSMakeRange(0, [name length])];
+
+  // Make the clean string immutable again and release the mutable object.
+  NSString* clean_name = [name copy];
+  [name release];
+
   if (node_) {
-    model->SetTitle(node_, base::SysNSStringToUTF16(name));
+    model->SetTitle(node_, base::SysNSStringToUTF16(clean_name));

[Ilya Sherman, 2011/11/18 22:51:29]

Since I don't think our other platforms can display multi-line titles either, it
probably makes sense to do the cleanup within the model, in both SetTitle and
AddFolder.  You might then be able to use one of the methods in
base/string_util.h to clean up the whitespace, e.g. the CollapseWhitespace()
method.

   } else {
     model->AddFolder(parent_,
                      newIndex_,
-                     base::SysNSStringToUTF16(name));
+                     base::SysNSStringToUTF16(clean_name));
   }
+
   [NSApp endSheet:[self window]];
 }
 
 - (void)didEndSheet:(NSWindow*)sheet
          returnCode:(int)returnCode
         contextInfo:(void*)contextInfo {
   [[self window] orderOut:self];
   observer_.reset(NULL);
   [self autorelease];
 }
 
 - (NSString*)folderName {
   return [nameField_ stringValue];
 }
 
 - (void)setFolderName:(NSString*)name {
   [nameField_ setStringValue:name];
 }
 
 - (NSButton*)okButton {
   return okButton_;
 }
 
 @end  // BookmarkNameFolderController