Fix content-encoding handling with buggy servers.

Some servers will serve compressed filetypes with "content-encoding: gzip"
because the file's contents were gzipped, even though the server is not
re-encoding the contents at all. The code in Filter::FixupEncodingTypes()
attempts to work around this by inferring whether the file is a gzip file with
bogus encoding based on the file extension in the URL, but this doesn't work
when the file being downloaded comes from a page whose extension doesn't reveal
the downloaded file type.

This change adds code to FixupEncodingTypes to also consider the download
filename, supplied by the "content-disposition" header, if any. This means that
we now behave correctly in the case where:

-> GET /foo.php?download
<- HTTP/1.1 200 OK
<- ...
<- Content-Disposition: attachment;filename="foo.tar.gz"
<- ...
<- Content-Encoding: gzip

BUG=83292
TEST=unit,trybot

Review URL: https://codereview.chromium.org/206503006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@258729 0039d316-1c4b-4281-b951-d872f2087c98

net/filter/filter.cc

@@ -8,6 +8,7 @@
 #include "base/strings/string_util.h"
 #include "net/base/io_buffer.h"
 #include "net/base/mime_util.h"
+#include "net/base/net_util.h"
 #include "net/filter/gzip_filter.h"
 #include "net/filter/sdch_filter.h"
 
@@ -170,11 +171,14 @@ void Filter::FixupEncodingTypes(
       encoding_types->clear();
 
     GURL url;
+    std::string disposition;
     success = filter_context.GetURL(&url);
     DCHECK(success);
-    base::FilePath filename =
-        base::FilePath().AppendASCII(url.ExtractFileName());
-    base::FilePath::StringType extension = filename.Extension();
+    filter_context.GetContentDisposition(&disposition);
+    // Don't supply a MIME type here, since that may cause disk IO.
+    base::FilePath filepath = GenerateFileName(url, disposition, "UTF-8", "",
+                                               "", "");
+    base::FilePath::StringType extension = filepath.Extension();
 
     if (filter_context.IsDownload()) {
       // We don't want to decompress gzipped files when the user explicitly

net/filter/filter.h

@@ -74,6 +74,10 @@ class NET_EXPORT_PRIVATE FilterContext {
   // Return false if gurl is not present.
   virtual bool GetURL(GURL* gurl) const = 0;
 
+  // What Content-Disposition header came with this data?
+  // Return false if no header was present.
+  virtual bool GetContentDisposition(std::string* disposition) const = 0;
+
   // When was this data requested from a server?
   virtual base::Time GetRequestTime() const = 0;
 

net/filter/filter_unittest.cc

@@ -82,6 +82,23 @@ TEST(FilterTest, ApacheGzip) {
   EXPECT_EQ(Filter::FILTER_TYPE_GZIP, encoding_types.front());
 }
 
+TEST(FilterTest, GzipContentDispositionFilename) {
+  MockFilterContext filter_context;
+  filter_context.SetSdchResponse(false);
+
+  const std::string kGzipMime("application/x-tar");
+  const std::string kContentDisposition("attachment; filename=\"foo.tgz\"");
+  const std::string kURL("http://foo.com/getfoo.php");
+  std::vector<Filter::FilterType> encoding_types;
+
+  encoding_types.push_back(Filter::FILTER_TYPE_GZIP);
+  filter_context.SetMimeType(kGzipMime);
+  filter_context.SetURL(GURL(kURL));
+  filter_context.SetContentDisposition(kContentDisposition);
+  Filter::FixupEncodingTypes(filter_context, &encoding_types);
+  ASSERT_EQ(0U, encoding_types.size());
+}
+
 TEST(FilterTest, SdchEncoding) {
   // Handle content encodings including SDCH.
   const std::string kTextHtmlMime("text/html");

net/filter/mock_filter_context.cc

@@ -27,6 +27,13 @@ bool MockFilterContext::GetURL(GURL* gurl) const {
   return true;
 }
 
+bool MockFilterContext::GetContentDisposition(std::string* disposition) const {
+  if (content_disposition_.empty())
+    return false;
+  *disposition = content_disposition_;
+  return true;
+}
+
 // What was this data requested from a server?
 base::Time MockFilterContext::GetRequestTime() const {
   return request_time_;

net/filter/mock_filter_context.h

@@ -19,6 +19,9 @@ class MockFilterContext : public FilterContext {
 
   void SetMimeType(const std::string& mime_type) { mime_type_ = mime_type; }
   void SetURL(const GURL& gurl) { gurl_ = gurl; }
+  void SetContentDisposition(const std::string& disposition) {
+    content_disposition_ = disposition;
+  }
   void SetRequestTime(const base::Time time) { request_time_ = time; }
   void SetCached(bool is_cached) { is_cached_content_ = is_cached; }
   void SetDownload(bool is_download) { is_download_ = is_download; }
@@ -33,6 +36,10 @@ class MockFilterContext : public FilterContext {
   // Return false if gurl is not present.
   virtual bool GetURL(GURL* gurl) const OVERRIDE;
 
+  // What Content-Disposition did the server supply for this data?
+  // Return false if Content-Disposition was not present.
+  virtual bool GetContentDisposition(std::string* disposition) const OVERRIDE;
+
   // What was this data requested from a server?
   virtual base::Time GetRequestTime() const OVERRIDE;
 
@@ -55,6 +62,7 @@ class MockFilterContext : public FilterContext {
  private:
   int buffer_size_;
   std::string mime_type_;
+  std::string content_disposition_;
   GURL gurl_;
   base::Time request_time_;
   bool is_cached_content_;

net/url_request/url_request_http_job.cc

@@ -25,6 +25,7 @@
 #include "net/base/sdch_manager.h"
 #include "net/cert/cert_status_flags.h"
 #include "net/cookies/cookie_monster.h"
+#include "net/http/http_content_disposition.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_response_headers.h"
@@ -58,6 +59,7 @@ class URLRequestHttpJob::HttpFilterContext : public FilterContext {
   // FilterContext implementation.
   virtual bool GetMimeType(std::string* mime_type) const OVERRIDE;
   virtual bool GetURL(GURL* gurl) const OVERRIDE;
+  virtual bool GetContentDisposition(std::string* disposition) const OVERRIDE;
   virtual base::Time GetRequestTime() const OVERRIDE;
   virtual bool IsCachedContent() const OVERRIDE;
   virtual bool IsDownload() const OVERRIDE;
@@ -96,6 +98,13 @@ bool URLRequestHttpJob::HttpFilterContext::GetURL(GURL* gurl) const {
   return true;
 }
 
+bool URLRequestHttpJob::HttpFilterContext::GetContentDisposition(
+    std::string* disposition) const {
+  HttpResponseHeaders* headers = job_->GetResponseHeaders();
+  void *iter = NULL;
+  return headers->EnumerateHeader(&iter, "Content-Disposition", disposition);
+}
+
 base::Time URLRequestHttpJob::HttpFilterContext::GetRequestTime() const {
   return job_->request() ? job_->request()->request_time() : base::Time();
 }