diff --git a/indra/cmake/Cwdebug.cmake b/indra/cmake/Cwdebug.cmake
index f68c7a897..d469386e1 100644
--- a/indra/cmake/Cwdebug.cmake
+++ b/indra/cmake/Cwdebug.cmake
@@ -2,7 +2,6 @@ include_directories (${CMAKE_SOURCE_DIR}/cwdebug)
 
 set(cwdebug_SOURCE_FILES
     ${CMAKE_SOURCE_DIR}/cwdebug/debug.cc
-    ${CMAKE_SOURCE_DIR}/cwdebug/debug_libcurl.cc
     )
 
 set(cwdebug_HEADER_FILES
@@ -10,7 +9,6 @@ set(cwdebug_HEADER_FILES
     ${CMAKE_SOURCE_DIR}/cwdebug/sys.h
     ${CMAKE_SOURCE_DIR}/cwdebug/debug.h
     ${CMAKE_SOURCE_DIR}/cwdebug/debug_ostream_operators.h
-    ${CMAKE_SOURCE_DIR}/cwdebug/debug_libcurl.h
     )
 
 set_source_files_properties(${cwdebug_HEADER_FILES}
diff --git a/indra/llmessage/CMakeLists.txt b/indra/llmessage/CMakeLists.txt
index b2b8eb4ec..aac669137 100644
--- a/indra/llmessage/CMakeLists.txt
+++ b/indra/llmessage/CMakeLists.txt
@@ -30,6 +30,7 @@ set(llmessage_SOURCE_FILES
     llcircuit.cpp
     llclassifiedflags.cpp
     aicurl.cpp
+    debug_libcurl.cpp
     aicurlthread.cpp
     lldatapacker.cpp
     lldispatcher.cpp
@@ -117,6 +118,7 @@ set(llmessage_HEADER_FILES
     llclassifiedflags.h
     llcurl.h
     aicurl.h
+    debug_libcurl.h
     aicurlprivate.h
     aicurlthread.h
     lldatapacker.h
diff --git a/indra/llmessage/aicurl.h b/indra/llmessage/aicurl.h
index 4752d1b45..895650ec8 100644
--- a/indra/llmessage/aicurl.h
+++ b/indra/llmessage/aicurl.h
@@ -37,11 +37,16 @@
 #include <stdexcept>
 #include <boost/intrusive_ptr.hpp>
 #include <boost/utility.hpp>
+
+#include "llpreprocessor.h"
 #include <curl/curl.h>		// Needed for files that include this header (also for aicurlprivate.h).
+#ifdef DEBUG_CURLIO
 #include "debug_libcurl.h"
+#endif
 
 // Make sure we don't use this option: it is not thread-safe.
 #undef CURLOPT_DNS_USE_GLOBAL_CACHE
+#define CURLOPT_DNS_USE_GLOBAL_CACHE do_not_use_CURLOPT_DNS_USE_GLOBAL_CACHE
 
 #include "stdtypes.h"		// U32
 #include "lliopipe.h"		// LLIOPipe::buffer_ptr_t
diff --git a/indra/llmessage/aicurlthread.cpp b/indra/llmessage/aicurlthread.cpp
index c03a0f309..4d56a0622 100644
--- a/indra/llmessage/aicurlthread.cpp
+++ b/indra/llmessage/aicurlthread.cpp
@@ -177,6 +177,19 @@ int closesocket(curl_socket_t fd)
   return close(fd);
 }
 
+int const FIONBIO = 0;
+
+int ioctlsocket(int fd, int, unsigned long* nonblocking_enable)
+{
+  int res = fcntl(fd, F_GETFL, 0);
+  llassert_always(res != -1);
+  if (*nonblocking_enable)
+	res |= O_NONBLOCK;
+  else
+	res &= ~O_NONBLOCK;
+  return fcntl(fd, F_SETFD, res);
+}
+
 #endif // DEBUG_WINDOWS_CODE_ON_LINUX
 
 #define WINDOWS_CODE (LL_WINDOWS || DEBUG_WINDOWS_CODE_ON_LINUX)
@@ -894,7 +907,7 @@ static int dumb_socketpair(SOCKET socks[2], bool make_overlapped)
     WSASetLastError(e);
     return SOCKET_ERROR;
 }
-#else
+#elif WINDOWS_CODE
 int dumb_socketpair(int socks[2], int dummy)
 {
     (void) dummy;
@@ -913,18 +926,18 @@ void AICurlThread::create_wakeup_fds(void)
 		llerrs << "Failed to generate wake-up socket pair" << formatWSAError() << llendl;
 		return;
 	}
-	u_long nonblocking_enable = TRUE;
-	int error = ioctlsocket(socks[0], FIONBIO, &nonblocking_enable);
-	if(error)
-	{
-		llerrs << "Failed to set wake-up socket nonblocking: " << formatWSAError() << llendl;
-	}
-	llassert(nonblocking_enable);
-	error = ioctlsocket(socks[1], FIONBIO, &nonblocking_enable);
-	if(error)
-	{
-		llerrs << "Failed to set wake-up input socket nonblocking: " << formatWSAError() << llendl;
-	}
+	u_long nonblocking_enable = TRUE;
+	int error = ioctlsocket(socks[0], FIONBIO, &nonblocking_enable);
+	if(error)
+	{
+		llerrs << "Failed to set wake-up socket nonblocking: " << formatWSAError() << llendl;
+	}
+	llassert(nonblocking_enable);
+	error = ioctlsocket(socks[1], FIONBIO, &nonblocking_enable);
+	if(error)
+	{
+		llerrs << "Failed to set wake-up input socket nonblocking: " << formatWSAError() << llendl;
+	}
 	mWakeUpFd = socks[0];
 	mWakeUpFd_in = socks[1];
 #else
@@ -933,7 +946,7 @@ void AICurlThread::create_wakeup_fds(void)
   {
 	llerrs << "Failed to create wakeup pipe: " << strerror(errno) << llendl;
   }
-  long flags = O_NONBLOCK;
+  int const flags = O_NONBLOCK;
   for (int i = 0; i < 2; ++i)
   {
 	if (fcntl(pipefd[i], F_SETFL, flags))
diff --git a/indra/cwdebug/debug_libcurl.cc b/indra/llmessage/debug_libcurl.cpp
similarity index 99%
rename from indra/cwdebug/debug_libcurl.cc
rename to indra/llmessage/debug_libcurl.cpp
index 05df113c8..b2bdd6f64 100644
--- a/indra/cwdebug/debug_libcurl.cc
+++ b/indra/llmessage/debug_libcurl.cpp
@@ -4,6 +4,8 @@
 #include <iostream>
 #include <iomanip>
 #include <stdarg.h>
+#include "llpreprocessor.h"
+#include <curl/curl.h>
 #define COMPILING_DEBUG_LIBCURL_CC
 #include "debug_libcurl.h"
 #include "../llcommon/llerror.h"
@@ -801,6 +803,7 @@ char* debug_curl_version(void)
 
 }
 
-#else
+#else	// DEBUG_CURLIO
 int debug_libcurl_dummy;	// I thought some OS didn't like empty source files.
-#endif
+#endif	// DEBUG_CURLIO
+
diff --git a/indra/cwdebug/debug_libcurl.h b/indra/llmessage/debug_libcurl.h
similarity index 91%
rename from indra/cwdebug/debug_libcurl.h
rename to indra/llmessage/debug_libcurl.h
index bcf15e0f0..98884f077 100644
--- a/indra/cwdebug/debug_libcurl.h
+++ b/indra/llmessage/debug_libcurl.h
@@ -1,9 +1,19 @@
 #ifndef DEBUG_LIBCURL
 #define DEBUG_LIBCURL
 
-#ifdef DEBUG_CURLIO
+#ifndef DEBUG_CURLIO
+#error "Don't include debug_libcurl.h unless DEBUG_CURLIO is defined."
+#endif
+
+#ifndef CURLINFO_TYPEMASK
+#error "<curl/curl.h> must be included before including debug_libcurl.h!"
+#endif
+
+#ifndef LLPREPROCESSOR_H
+// CURL_STATICLIB is needed on windows namely, which is defined in llpreprocessor.h (but only on windows).
+#error "llpreprocessor.h must be included before <curl/curl.h>."
+#endif
 
-#include <curl/curl.h>
 #include "debug.h"
 
 extern "C" {
@@ -78,6 +88,4 @@ extern CWD_API char* debug_curl_version(void);
 
 #endif // !COMPILING_DEBUG_LIBCURL_CC
 
-#endif // DEBUG_CURLIO
-
 #endif // DEBUG_LIBCURL
diff --git a/indra/newview/hipporestrequest.cpp b/indra/newview/hipporestrequest.cpp
index 4cd0cc34c..60d7770a1 100644
--- a/indra/newview/hipporestrequest.cpp
+++ b/indra/newview/hipporestrequest.cpp
@@ -8,14 +8,16 @@
 #endif
 
 #include <stdtypes.h>
-#include <llbufferstream.h>
-#include <llerror.h>
-#include <llhttpclient.h>
-#include <llurlrequest.h>
-#include <llxmltree.h>
+#include "llbufferstream.h"
+#include "llerror.h"
+#include "llhttpclient.h"
+#include "llurlrequest.h"
+#include "llxmltree.h"
 
 #include <curl/curl.h>
+#ifdef DEBUG_CURLIO
 #include "debug_libcurl.h"
+#endif
 
 // ********************************************************************
  
diff --git a/indra/newview/llurlsimstring.cpp b/indra/newview/llurlsimstring.cpp
index a28988db5..200345cae 100644
--- a/indra/newview/llurlsimstring.cpp
+++ b/indra/newview/llurlsimstring.cpp
@@ -38,7 +38,10 @@
 #include "llpanellogin.h"
 #include "llviewercontrol.h"
 
-#include "curl/curl.h"
+#include <curl/curl.h>			// curl_unescape, curl_free
+#ifdef DEBUG_CURLIO
+#include "debug_libcurl.h"
+#endif
 
 //static
 LLURLSimString LLURLSimString::sInstance;
diff --git a/indra/newview/llwaterparammanager.cpp b/indra/newview/llwaterparammanager.cpp
index ab95ee14d..307edffdd 100644
--- a/indra/newview/llwaterparammanager.cpp
+++ b/indra/newview/llwaterparammanager.cpp
@@ -76,8 +76,6 @@
 
 #include "llagentcamera.h"
 
-#include "curl/curl.h"
-
 LLWaterParamManager::LLWaterParamManager() :
 	mFogColor(22.f/255.f, 43.f/255.f, 54.f/255.f, 0.0f, 0.0f, "waterFogColor", "WaterFogColor"),
 	mFogDensity(4, "waterFogDensity", 2),