net/ftp: Fix control response parsing for a corner cases where the first line of a continuation has 0 length.

BUG=29322
TEST=ftp://sourceware.org works.
Review URL: http://codereview.chromium.org/467032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33986 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 42 insertions, 17 deletions

diff --git a/net/ftp/ftp_ctrl_response_buffer.cc b/net/ftp/ftp_ctrl_response_buffer.cc
index 02bbd08..8ea58cc 100644
--- a/net/ftp/ftp_ctrl_response_buffer.cc
+++ b/net/ftp/ftp_ctrl_response_buffer.cc
@@ -21,22 +21,7 @@ int FtpCtrlResponseBuffer::ConsumeData(const char* data, int data_length) {
     ParsedLine line = lines_.front();
     lines_.pop();
 
-    if (line_buf_.empty()) {
-      if (!line.is_complete)
-        return ERR_INVALID_RESPONSE;
-
-      response_buf_.status_code = line.status_code;
-      if (line.is_multiline) {
-        line_buf_ = line.status_text;
-      } else {
-        response_buf_.lines.push_back(line.status_text);
-        responses_.push(response_buf_);
-
-        // Prepare to handle following lines.
-        response_buf_ = FtpCtrlResponse();
-        line_buf_.clear();
-      }
-    } else {
+    if (multiline_) {
       if (!line.is_complete || line.status_code != response_buf_.status_code) {
         line_buf_.append(line.raw_text);
         continue;
@@ -54,6 +39,23 @@ int FtpCtrlResponseBuffer::ConsumeData(const char* data, int data_length) {
         // Prepare to handle following lines.
         response_buf_ = FtpCtrlResponse();
         line_buf_.clear();
+        multiline_ = false;
+      }
+    } else {
+      if (!line.is_complete)
+        return ERR_INVALID_RESPONSE;
+
+      response_buf_.status_code = line.status_code;
+      if (line.is_multiline) {
+        line_buf_ = line.status_text;
+        multiline_ = true;
+      } else {
+        response_buf_.lines.push_back(line.status_text);
+        responses_.push(response_buf_);
+
+        // Prepare to handle following lines.
+        response_buf_ = FtpCtrlResponse();
+        line_buf_.clear();
       }
     }
   }
diff --git a/net/ftp/ftp_ctrl_response_buffer.h b/net/ftp/ftp_ctrl_response_buffer.h
index 66aae8b..6ea34cb 100644
--- a/net/ftp/ftp_ctrl_response_buffer.h
+++ b/net/ftp/ftp_ctrl_response_buffer.h
@@ -24,7 +24,8 @@ struct FtpCtrlResponse {
 
 class FtpCtrlResponseBuffer {
  public:
-  FtpCtrlResponseBuffer() {}
+  FtpCtrlResponseBuffer() : multiline_(false) {
+  }
 
   // Called when data is received from the control socket. Returns error code.
   int ConsumeData(const char* data, int data_length);
@@ -81,6 +82,9 @@ class FtpCtrlResponseBuffer {
 
   std::queue<ParsedLine> lines_;
 
+  // True if we are in the middle of parsing a multi-line response.
+  bool multiline_;
+
   // When parsing a multiline response, we don't know beforehand if a line
   // will have a continuation. So always store last line of multiline response
   // so we can append the continuation to it.
diff --git a/net/ftp/ftp_ctrl_response_buffer_unittest.cc b/net/ftp/ftp_ctrl_response_buffer_unittest.cc
index c2aeee2..1477c09 100644
--- a/net/ftp/ftp_ctrl_response_buffer_unittest.cc
+++ b/net/ftp/ftp_ctrl_response_buffer_unittest.cc
@@ -96,6 +96,25 @@ TEST_F(FtpCtrlResponseBufferTest, MultilineContinuation) {
   EXPECT_EQ("LastLine", response.lines[2]);
 }
 
+TEST_F(FtpCtrlResponseBufferTest, MultilineContinuationZeroLength) {
+  // For the corner case from bug 29322.
+  EXPECT_EQ(net::OK, PushDataToBuffer("230-\r\n"));
+  EXPECT_FALSE(buffer_.ResponseAvailable());
+
+  EXPECT_EQ(net::OK, PushDataToBuffer("example.com\r\n"));
+  EXPECT_FALSE(buffer_.ResponseAvailable());
+
+  EXPECT_EQ(net::OK, PushDataToBuffer("230 LastLine\r\n"));
+  EXPECT_TRUE(buffer_.ResponseAvailable());
+
+  net::FtpCtrlResponse response = buffer_.PopResponse();
+  EXPECT_FALSE(buffer_.ResponseAvailable());
+  EXPECT_EQ(230, response.status_code);
+  ASSERT_EQ(2U, response.lines.size());
+  EXPECT_EQ("example.com", response.lines[0]);
+  EXPECT_EQ("LastLine", response.lines[1]);
+}
+
 TEST_F(FtpCtrlResponseBufferTest, SimilarContinuation) {
   EXPECT_EQ(net::OK, PushDataToBuffer("230-FirstLine\r\n"));
   EXPECT_FALSE(buffer_.ResponseAvailable());