#2565: HTMLForm: optional enforcement of Content-Length instead of Chunked Transfer-Encoding

Net/include/Poco/Net/HTMLForm.h

@@ -46,6 +46,12 @@ class Net_API HTMLForm: public NameValueCollection
 	/// form fields programmatically. The default limit is 100.
 {
 public:
+	enum Options
+	{
+		OPT_USE_CONTENT_LENGTH = 0x01
+			/// Don't use Chunked Transfer-Encoding for multipart requests.
+	};
+
 	HTMLForm();
 		/// Creates an empty HTMLForm and sets the
 		/// encoding to "application/x-www-form-urlencoded".
@@ -137,7 +143,7 @@ public:
 		/// Note that read() does not clear the form before
 		/// reading the new values.
 
-	void prepareSubmit(HTTPRequest& request);
+	void prepareSubmit(HTTPRequest& request, int options = 0);
 		/// Fills out the request object for submitting the form.
 		///
 		/// If the request method is GET, the encoded form is appended to the
@@ -150,7 +156,12 @@ public:
 		///    - the content transfer encoding is set to identity encoding
 		/// Otherwise, if the request's HTTP version is HTTP/1.1:
 		///    - the request's persistent connection state is left unchanged
-		///    - the content transfer encoding is set to chunked
+		///    - the content transfer encoding is set to chunked, unless
+		///      the OPT_USE_CONTENT_LENGTH is given in options
+		///
+		/// Note: Not using chunked transfer encoding for multipart forms
+		/// degrades performance, as the request content must be generated
+		/// twice, first to determine its size, then to actually send it.
 
 	std::streamsize calculateContentLength();
 		/// Calculate the content length for the form.

Net/src/HTMLForm.cpp

@@ -203,7 +203,7 @@ void HTMLForm::read(const std::string& queryString)
 }
 
 
-void HTMLForm::prepareSubmit(HTTPRequest& request)
+void HTMLForm::prepareSubmit(HTTPRequest& request, int options)
 {
 	if (request.getMethod() == HTTPRequest::HTTP_POST || request.getMethod() == HTTPRequest::HTTP_PUT)
 	{
@@ -229,11 +229,11 @@ void HTMLForm::prepareSubmit(HTTPRequest& request)
 			request.setKeepAlive(false);
 			request.setChunkedTransferEncoding(false);
 		}
-		else if (_encoding != ENCODING_URL)
+		else if (_encoding != ENCODING_URL && (options & OPT_USE_CONTENT_LENGTH) == 0)
 		{
 			request.setChunkedTransferEncoding(true);
 		}
-		if (!request.getChunkedTransferEncoding())
+		if (!request.getChunkedTransferEncoding() && !request.hasContentLength())
  		{
  			request.setContentLength(calculateContentLength());
  		}

Net/testsuite/src/HTMLFormTest.cpp

@@ -19,6 +19,7 @@
 #include "Poco/Net/NetException.h"
 #include <sstream>
 
+#include <iostream>
 
 using Poco::Net::HTMLForm;
 using Poco::Net::PartSource;
@@ -294,6 +295,7 @@ void HTMLFormTest::testSubmit2()
 	HTTPRequest req("POST", "/form.cgi");
 	form.prepareSubmit(req);
 	assertTrue (req.getContentType() == HTMLForm::ENCODING_URL);
+	assertTrue (req.getContentLength() == 64);
 }
 
 
@@ -331,6 +333,25 @@ void HTMLFormTest::testSubmit4()
 }
 
 
+void HTMLFormTest::testSubmit5()
+{
+	HTMLForm form(HTMLForm::ENCODING_MULTIPART);
+	form.set("field1", "value1");
+	form.set("field2", "value 2");
+	form.set("field3", "value=3");
+	form.set("field4", "value&4");
+
+	HTTPRequest req("POST", "/form.cgi", HTTPMessage::HTTP_1_1);
+	form.prepareSubmit(req, HTMLForm::OPT_USE_CONTENT_LENGTH);
+	std::string expCT(HTMLForm::ENCODING_MULTIPART);
+	expCT.append("; boundary=\"");
+	expCT.append(form.boundary());
+	expCT.append("\"");
+	assertTrue (req.getContentType() == expCT);
+	assertTrue (req.getContentLength() == 403);
+}
+
+
 void HTMLFormTest::testFieldLimitUrl()
 {
 	HTTPRequest req("GET", "/form.cgi?field1=value1&field2=value%202&field3=value%3D3&field4=value%264");
@@ -416,6 +437,7 @@ CppUnit::Test* HTMLFormTest::suite()
 	CppUnit_addTest(pSuite, HTMLFormTest, testSubmit2);
 	CppUnit_addTest(pSuite, HTMLFormTest, testSubmit3);
 	CppUnit_addTest(pSuite, HTMLFormTest, testSubmit4);
+	CppUnit_addTest(pSuite, HTMLFormTest, testSubmit5);
 	CppUnit_addTest(pSuite, HTMLFormTest, testFieldLimitUrl);
 	CppUnit_addTest(pSuite, HTMLFormTest, testFieldLimitMultipart);
 

Net/testsuite/src/HTMLFormTest.h

@@ -36,6 +36,7 @@ public:
 	void testSubmit2();
 	void testSubmit3();
 	void testSubmit4();
+	void testSubmit5();
 	void testFieldLimitUrl();
 	void testFieldLimitMultipart();