This CL makes Chrome on par with Firefox in terms of 'GetSuggestedFilename' for file download via context-menu.

For a download initiated with a click on a link in a web page, a webkit-side change is necessary, which will be done later.

Add a field (referrer_charset) to URLRequestContext and DownloadCreateInfo. It's set to the character encoding of a document where the download request originates from when it's known (download initiated via "save as" in the context menu). 

If it's not known (a download initiated by clicking on a download link or typing a url directly to the omnibox), it's initialized to the default character encoding in the user's preference. I guess this is marginally better than leaving it empty (in that case, step 2b below will be skipped and step 2c will be taken) because a user has a better control over how raw 8bit characters in C-D are interpreted (especially on Windows where a reboot is required to change the OS default codepage). 

This is later passed to GetSuggestedFilename and used as one of fallback encodings (1. UTF-8, 2. origin_charset, 3. default OS codepage). With this change, we support the following:

1. RFC 2047
2. Raw-8bit-characters : a. UTF-8, b. origin_charset, c. default os codepage. 
3. %-escaped UTF-8. 

In this CL, for #3, I didn't add a fallback similar to one used for #2. If necessary, it can be added easily. New entries are added to 3 existing tests. What's previously not covered (raw 8bit Content-Disposition header) is now covered in all 3 tests. 

BUG=1148
TEST=net unit test: NetUtilTest.GetFileNameFromCD                    
                    NetUtilTest.GetSuggestedFilename         
     unittest : DownloadManagerTest.TestDownloadFilename

Review URL: http://codereview.chromium.org/83002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@15113 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 14 insertions, 0 deletions

diff --git a/chrome/browser/net/chrome_url_request_context.cc b/chrome/browser/net/chrome_url_request_context.cc
index ac5c3c3..b15db26 100644
--- a/chrome/browser/net/chrome_url_request_context.cc
+++ b/chrome/browser/net/chrome_url_request_context.cc
@@ -198,6 +198,20 @@ ChromeURLRequestContext::ChromeURLRequestContext(Profile* profile)
   accept_charset_ = net::HttpUtil::GenerateAcceptCharsetHeader(
       WideToASCII(prefs_->GetString(prefs::kDefaultCharset)));
 
+  // At this point, we don't know the charset of the referring page
+  // where a url request originates from. This is used to get a suggested
+  // filename from Content-Disposition header made of raw 8bit characters.
+  // Down the road, it can be overriden if it becomes known (for instance,
+  // when download request is made through the context menu in a web page).
+  // At the moment, it'll remain 'undeterministic' when a user
+  // types a URL in the omnibar or click on a download link in a page.
+  // For the latter, we need a change on the webkit-side.
+  // We initialize it to the default charset here and a user will
+  // have an *arguably* better default charset for interpreting a raw 8bit
+  // C-D header field.  It means the native OS codepage fallback in
+  // net_util::GetSuggestedFilename is unlikely to be taken.
+  referrer_charset_ = accept_charset_;
+
   cookie_policy_.SetType(net::CookiePolicy::FromInt(
       prefs_->GetInteger(prefs::kCookieBehavior)));