diff --git a/glib/poppler-input-stream.cc b/glib/poppler-input-stream.cc
index 99fcb6f..4ac3149 100644
--- a/glib/poppler-input-stream.cc
+++ b/glib/poppler-input-stream.cc
@@ -41,6 +41,10 @@ PopplerInputStream::~PopplerInputStream()
     g_object_unref(cancellable);
 }
 
+BaseStream *PopplerInputStream::copy() {
+  return new PopplerInputStream(inputStream, cancellable, start, limited, length, &dict);
+}
+
 Stream *PopplerInputStream::makeSubStream(Guint startA, GBool limitedA,
                                           Guint lengthA, Object *dictA)
 {
diff --git a/glib/poppler-input-stream.h b/glib/poppler-input-stream.h
index 0d795f4..639ea04 100644
--- a/glib/poppler-input-stream.h
+++ b/glib/poppler-input-stream.h
@@ -33,6 +33,7 @@ public:
   PopplerInputStream(GInputStream *inputStream, GCancellable *cancellableA,
                      Guint startA, GBool limitedA, Guint lengthA, Object *dictA);
   virtual ~PopplerInputStream();
+  virtual BaseStream *copy();
   virtual Stream *makeSubStream(Guint start, GBool limited,
                                 Guint lengthA, Object *dictA);
   virtual StreamKind getKind() { return strWeird; }
diff --git a/poppler/CairoFontEngine.cc b/poppler/CairoFontEngine.cc
index c4493e8..2dd241a 100644
--- a/poppler/CairoFontEngine.cc
+++ b/poppler/CairoFontEngine.cc
@@ -645,7 +645,7 @@ _render_type3_glyph (cairo_scaled_font_t  *scaled_font,
   box.y2 = mat[3];
   gfx = new Gfx(info->doc, output_dev, resDict, &box, NULL);
   output_dev->startDoc(info->doc, info->fontEngine);
-  output_dev->startPage (1, gfx->getState());
+  output_dev->startPage (1, gfx->getState(), gfx->getXRef());
   output_dev->setInType3Char(gTrue);
   gfx->display(charProcs->getVal(glyph, &charProc));
 
diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index b70183e..751b08c 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -236,7 +236,7 @@ void CairoOutputDev::startDoc(PDFDoc *docA,
   }
 }
 
-void CairoOutputDev::startPage(int pageNum, GfxState *state) {
+void CairoOutputDev::startPage(int pageNum, GfxState *state, XRef *xref) {
   /* set up some per page defaults */
   cairo_pattern_destroy(fill_pattern);
   cairo_pattern_destroy(stroke_pattern);
diff --git a/poppler/CairoOutputDev.h b/poppler/CairoOutputDev.h
index df76975..548fab5 100644
--- a/poppler/CairoOutputDev.h
+++ b/poppler/CairoOutputDev.h
@@ -124,7 +124,7 @@ public:
   //----- initialization and control
 
   // Start a page.
-  virtual void startPage(int pageNum, GfxState *state);
+  virtual void startPage(int pageNum, GfxState *state, XRef *xref);
 
   // End a page.
   virtual void endPage();
diff --git a/poppler/Gfx.cc b/poppler/Gfx.cc
index d7684d6..5ce0dac 100644
--- a/poppler/Gfx.cc
+++ b/poppler/Gfx.cc
@@ -533,7 +533,7 @@ Gfx::Gfx(PDFDoc *docA, OutputDev *outA, int pageNum, Dict *resDict,
 	 double hDPI, double vDPI, PDFRectangle *box,
 	 PDFRectangle *cropBox, int rotate,
 	 GBool (*abortCheckCbkA)(void *data),
-	 void *abortCheckCbkDataA)
+	 void *abortCheckCbkDataA, GBool fCopy)
 #ifdef USE_CMS
  : iccColorSpaceCache(5)
 #endif
@@ -541,7 +541,8 @@ Gfx::Gfx(PDFDoc *docA, OutputDev *outA, int pageNum, Dict *resDict,
   int i;
 
   doc = docA;
-  xref = doc->getXRef();
+  xref = (fCopy) ? doc->getXRef()->copy() : doc->getXRef();
+  xrefOwner = fCopy;
   catalog = doc->getCatalog();
   subPage = gFalse;
   printCommands = globalParams->getPrintCommands();
@@ -560,7 +561,7 @@ Gfx::Gfx(PDFDoc *docA, OutputDev *outA, int pageNum, Dict *resDict,
   fontChanged = gFalse;
   clip = clipNone;
   ignoreUndef = 0;
-  out->startPage(pageNum, state);
+  out->startPage(pageNum, state, xref);
   out->setDefaultCTM(state->getCTM());
   out->updateAll(state);
   for (i = 0; i < 6; ++i) {
@@ -604,6 +605,7 @@ Gfx::Gfx(PDFDoc *docA, OutputDev *outA, Dict *resDict,
   profileCommands = globalParams->getProfileCommands();
   mcStack = NULL;
   parser = NULL;
+  xrefOwner = gFalse;
 
   // start the resource stack
   res = new GfxResources(xref, resDict, NULL);
@@ -658,6 +660,8 @@ Gfx::~Gfx() {
   while (mcStack) {
     popMarkedContent();
   }
+  if (xrefOwner)
+    delete xref;
 }
 
 void Gfx::display(Object *obj, GBool topLevel) {
diff --git a/poppler/Gfx.h b/poppler/Gfx.h
index 37022e0..5b9348a 100644
--- a/poppler/Gfx.h
+++ b/poppler/Gfx.h
@@ -148,7 +148,7 @@ public:
       double hDPI, double vDPI, PDFRectangle *box,
       PDFRectangle *cropBox, int rotate,
       GBool (*abortCheckCbkA)(void *data) = NULL,
-      void *abortCheckCbkDataA = NULL);
+      void *abortCheckCbkDataA = NULL, GBool fCopy = gFalse);
 
   // Constructor for a sub-page object.
   Gfx(PDFDoc *docA, OutputDev *outA, Dict *resDict,
@@ -158,6 +158,8 @@ public:
 
   ~Gfx();
 
+  XRef *getXRef() { return xref; }
+
   // Interpret a stream or array of streams.
   void display(Object *obj, GBool topLevel = gTrue);
 
@@ -228,6 +230,7 @@ private:
   MarkedContentStack *mcStack;	// current BMC/EMC stack
 
   Parser *parser;		// parser for page content stream(s)
+  GBool xrefOwner;  // true if xref is owned by the instance
 
 #ifdef USE_CMS
   PopplerCache iccColorSpaceCache;
diff --git a/poppler/GlobalParamsWin.cc b/poppler/GlobalParamsWin.cc
index 527f08e..20d83ab 100644
--- a/poppler/GlobalParamsWin.cc
+++ b/poppler/GlobalParamsWin.cc
@@ -470,7 +470,7 @@ void GlobalParams::setupBaseFonts(char * dir)
       obj1.initNull();
       parser = new Parser(NULL,
 	      new Lexer(NULL,
-	      new FileStream(file, 0, gFalse, size, &obj1)),
+	      new FileStream(file, fileName->getCString(), 0, gFalse, size, &obj1)),
 	      gTrue);
       obj1.free();
       parser->getObj(&obj1);
diff --git a/poppler/OutputDev.h b/poppler/OutputDev.h
index 15af90a..9144418 100644
--- a/poppler/OutputDev.h
+++ b/poppler/OutputDev.h
@@ -132,7 +132,7 @@ public:
     { return gTrue; }
 
   // Start a page.
-  virtual void startPage(int pageNum, GfxState *state) {}
+  virtual void startPage(int pageNum, GfxState *state, XRef *xref) {}
 
   // End a page.
   virtual void endPage() {}
diff --git a/poppler/PDFDoc.cc b/poppler/PDFDoc.cc
index ce01ca3..a0e3827 100644
--- a/poppler/PDFDoc.cc
+++ b/poppler/PDFDoc.cc
@@ -75,6 +75,14 @@
 #include "PDFDoc.h"
 #include "Hints.h"
 
+#if MULTITHREADED
+#  define lockPDFDoc   gLockMutex(&mutex)
+#  define unlockPDFDoc gUnlockMutex(&mutex)
+#else
+#  define lockPDFDoc
+#  define unlockPDFDoc
+#endif
+
 //------------------------------------------------------------------------
 
 #define headerSearchSize 1024	// read this many bytes at beginning of
@@ -94,6 +102,9 @@
 
 void PDFDoc::init()
 {
+#if MULTITHREADED
+  gInitMutex(&mutex);
+#endif
   ok = gFalse;
   errCode = errNone;
   fileName = NULL;
@@ -160,7 +171,7 @@ PDFDoc::PDFDoc(GooString *fileNameA, GooString *ownerPassword,
 
   // create stream
   obj.initNull();
-  str = new FileStream(file, 0, gFalse, size, &obj);
+  str = new FileStream(file, fileName->getCString(), 0, gFalse, size, &obj);
 
   ok = setup(ownerPassword, userPassword);
 }
@@ -211,7 +222,7 @@ PDFDoc::PDFDoc(wchar_t *fileNameA, int fileNameLen, GooString *ownerPassword,
 
   // create stream
   obj.initNull();
-  str = new FileStream(file, 0, gFalse, size, &obj);
+  str = new FileStream(file, fileName->getCString(), 0, gFalse, size, &obj);
 
   ok = setup(ownerPassword, userPassword);
 }
@@ -491,14 +502,14 @@ void PDFDoc::displayPageSlice(OutputDev *out, int page,
 			      GBool (*abortCheckCbk)(void *data),
 			      void *abortCheckCbkData,
                               GBool (*annotDisplayDecideCbk)(Annot *annot, void *user_data),
-                              void *annotDisplayDecideCbkData) {
+                              void *annotDisplayDecideCbkData, GBool fMT) {
   if (getPage(page))
     getPage(page)->displaySlice(out, hDPI, vDPI,
 					 rotate, useMediaBox, crop,
 					 sliceX, sliceY, sliceW, sliceH,
 					 printing,
 					 abortCheckCbk, abortCheckCbkData,
-					 annotDisplayDecideCbk, annotDisplayDecideCbkData);
+					 annotDisplayDecideCbk, annotDisplayDecideCbkData, fMT);
 }
 
 Links *PDFDoc::getLinks(int page) {
@@ -661,7 +672,7 @@ int PDFDoc::savePageAs(GooString *name, int pageNo)
   infoObj.free();
   
   // get and mark output intents etc.
-  Object catObj, pagesObj, resourcesObj;
+  Object catObj, pagesObj, resourcesObj; 
   getXRef()->getCatalog(&catObj);
   Dict *catDict = catObj.getDict();
   catDict->lookup("Pages", &pagesObj);
@@ -701,7 +712,7 @@ int PDFDoc::savePageAs(GooString *name, int pageNo)
   outStr->printf("<< /Type /Pages /Kids [ %d 0 R ] /Count 1 ", rootNum + 2);
   if (resourcesObj.isDict()) {
     outStr->printf("/Resources ");
-    writeObject(&resourcesObj, NULL, outStr, getXRef(), 0);
+    writeObject(&resourcesObj, NULL, outStr, getXRef(), 0); 
     resourcesObj.free();
   }
   outStr->printf(">>\n");
@@ -1621,6 +1632,7 @@ Page *PDFDoc::parsePage(int page)
 
 Page *PDFDoc::getPage(int page)
 {
+  lockPDFDoc;
   if ((page < 1) || page > getNumPages()) return NULL;
 
   if (isLinearized()) {
@@ -1640,5 +1652,7 @@ Page *PDFDoc::getPage(int page)
     }
   }
 
-  return catalog->getPage(page);
+  Page *pageObj = catalog->getPage(page);
+  unlockPDFDoc;
+  return pageObj;
 }
diff --git a/poppler/PDFDoc.h b/poppler/PDFDoc.h
index 468f698..df96f6a 100644
--- a/poppler/PDFDoc.h
+++ b/poppler/PDFDoc.h
@@ -43,6 +43,7 @@
 #include "Page.h"
 #include "Annot.h"
 #include "OptionalContent.h"
+#include "goo/GooMutex.h"
 
 class GooString;
 class BaseStream;
@@ -164,7 +165,7 @@ public:
 			GBool (*abortCheckCbk)(void *data) = NULL,
 			void *abortCheckCbkData = NULL,
                         GBool (*annotDisplayDecideCbk)(Annot *annot, void *user_data) = NULL,
-                        void *annotDisplayDecideCbkData = NULL);
+                        void *annotDisplayDecideCbkData = NULL, GBool fMT = gFalse);
 
   // Find a page, given its object ID.  Returns page number, or 0 if
   // not found.
@@ -317,6 +318,9 @@ private:
   int fopenErrno;
 
   Guint startXRefPos;		// offset of last xref table
+#if MULTITHREADED
+  GooMutex mutex;
+#endif
 };
 
 #endif
diff --git a/poppler/PSOutputDev.cc b/poppler/PSOutputDev.cc
index f414897..f01cb15 100644
--- a/poppler/PSOutputDev.cc
+++ b/poppler/PSOutputDev.cc
@@ -3086,7 +3086,7 @@ GBool PSOutputDev::checkPageSlice(Page *page, double /*hDPI*/, double /*vDPI*/,
     rotateA += 360;
   }
   state = new GfxState(dpi, dpi, &box, rotateA, gFalse);
-  startPage(page->getNum(), state);
+  startPage(page->getNum(), state, NULL);
   delete state;
 
   // set up the SplashOutputDev
@@ -3472,7 +3472,7 @@ GBool PSOutputDev::checkPageSlice(Page *page, double /*hDPI*/, double /*vDPI*/,
 #endif // HAVE_SPLASH
 }
 
-void PSOutputDev::startPage(int pageNum, GfxState *state) {
+void PSOutputDev::startPage(int pageNum, GfxState *state, XRef * /*xref*/) {
   Page *page;
   int x1, y1, x2, y2, width, height, t;
   int imgWidth, imgHeight, imgWidth2, imgHeight2;
diff --git a/poppler/PSOutputDev.h b/poppler/PSOutputDev.h
index 809f058..7ee6b1d 100644
--- a/poppler/PSOutputDev.h
+++ b/poppler/PSOutputDev.h
@@ -85,7 +85,7 @@ enum PSOutCustomCodeLocation {
 typedef void (*PSOutputFunc)(void *stream, const char *data, int len);
 
 typedef GooString *(*PSOutCustomCodeCbk)(PSOutputDev *psOut,
-				       PSOutCustomCodeLocation loc, int n, 
+				       PSOutCustomCodeLocation loc, int n,
 				       void *data);
 
 class PSOutputDev: public OutputDev {
@@ -184,7 +184,7 @@ public:
 			       void *annotDisplayDecideCbkData = NULL);
 
   // Start a page.
-  virtual void startPage(int pageNum, GfxState *state);
+  virtual void startPage(int pageNum, GfxState *state, XRef *xref);
 
   // End a page.
   virtual void endPage();
@@ -417,7 +417,7 @@ private:
   void (*overlayCbk)(PSOutputDev *psOut, void *data);
   void *overlayCbkData;
   GooString *(*customCodeCbk)(PSOutputDev *psOut,
-			    PSOutCustomCodeLocation loc, int n, 
+			    PSOutCustomCodeLocation loc, int n,
 			    void *data);
   void *customCodeCbkData;
 
diff --git a/poppler/Page.cc b/poppler/Page.cc
index 87bc3a4..3097716 100644
--- a/poppler/Page.cc
+++ b/poppler/Page.cc
@@ -456,7 +456,7 @@ Gfx *Page::createGfx(OutputDev *out, double hDPI, double vDPI,
 		     int sliceX, int sliceY, int sliceW, int sliceH,
 		     GBool printing,
 		     GBool (*abortCheckCbk)(void *data),
-		     void *abortCheckCbkData) {
+		     void *abortCheckCbkData, GBool fMT) {
   PDFRectangle *mediaBox, *cropBox;
   PDFRectangle box;
   Gfx *gfx;
@@ -483,7 +483,7 @@ Gfx *Page::createGfx(OutputDev *out, double hDPI, double vDPI,
 
   gfx = new Gfx(doc, out, num, attrs->getResourceDict(),
 		hDPI, vDPI, &box, crop ? cropBox : (PDFRectangle *)NULL,
-		rotate, abortCheckCbk, abortCheckCbkData);
+		rotate, abortCheckCbk, abortCheckCbkData, fMT);
 
   return gfx;
 }
@@ -495,7 +495,7 @@ void Page::displaySlice(OutputDev *out, double hDPI, double vDPI,
 			GBool (*abortCheckCbk)(void *data),
 			void *abortCheckCbkData,
                         GBool (*annotDisplayDecideCbk)(Annot *annot, void *user_data),
-                        void *annotDisplayDecideCbkData) {
+                        void *annotDisplayDecideCbkData, GBool fMT) {
   Gfx *gfx;
   Object obj;
   Annots *annotList;
@@ -512,9 +512,9 @@ void Page::displaySlice(OutputDev *out, double hDPI, double vDPI,
   gfx = createGfx(out, hDPI, vDPI, rotate, useMediaBox, crop,
 		  sliceX, sliceY, sliceW, sliceH,
 		  printing,
-		  abortCheckCbk, abortCheckCbkData);
+		  abortCheckCbk, abortCheckCbkData, fMT);
 
-  contents.fetch(xref, &obj);
+  contents.fetch(gfx->getXRef(), &obj);
   if (!obj.isNull()) {
     gfx->saveState();
     gfx->display(&obj);
diff --git a/poppler/Page.h b/poppler/Page.h
index 78cedc4..352b6d9 100644
--- a/poppler/Page.h
+++ b/poppler/Page.h
@@ -208,7 +208,7 @@ public:
 		 int sliceX, int sliceY, int sliceW, int sliceH,
 		 GBool printing,
 		 GBool (*abortCheckCbk)(void *data),
-		 void *abortCheckCbkData);
+		 void *abortCheckCbkData, GBool fMT = gFalse);
 
   // Display a page.
   void display(OutputDev *out, double hDPI, double vDPI,
@@ -227,7 +227,7 @@ public:
 		    GBool (*abortCheckCbk)(void *data) = NULL,
 		    void *abortCheckCbkData = NULL,
                     GBool (*annotDisplayDecideCbk)(Annot *annot, void *user_data) = NULL,
-                    void *annotDisplayDecideCbkData = NULL);
+                    void *annotDisplayDecideCbkData = NULL, GBool fMT = gFalse);
 
   void display(Gfx *gfx);
 
diff --git a/poppler/PreScanOutputDev.cc b/poppler/PreScanOutputDev.cc
index 3a86d52..2512cc7 100644
--- a/poppler/PreScanOutputDev.cc
+++ b/poppler/PreScanOutputDev.cc
@@ -52,7 +52,7 @@ PreScanOutputDev::PreScanOutputDev(PDFDoc *docA) {
 PreScanOutputDev::~PreScanOutputDev() {
 }
 
-void PreScanOutputDev::startPage(int /*pageNum*/, GfxState * /*state*/) {
+void PreScanOutputDev::startPage(int /*pageNum*/, GfxState * /*state*/, XRef * /*xref*/) {
 }
 
 void PreScanOutputDev::endPage() {
diff --git a/poppler/PreScanOutputDev.h b/poppler/PreScanOutputDev.h
index 5260a3b..6b9b6b2 100644
--- a/poppler/PreScanOutputDev.h
+++ b/poppler/PreScanOutputDev.h
@@ -76,7 +76,7 @@ public:
   //----- initialization and control
 
   // Start a page.
-  virtual void startPage(int pageNum, GfxState *state);
+  virtual void startPage(int pageNum, GfxState *state, XRef *xref);
 
   // End a page.
   virtual void endPage();
diff --git a/poppler/SplashOutputDev.cc b/poppler/SplashOutputDev.cc
index 9e07060..58cab2c 100644
--- a/poppler/SplashOutputDev.cc
+++ b/poppler/SplashOutputDev.cc
@@ -1238,6 +1238,7 @@ SplashOutputDev::SplashOutputDev(SplashColorMode colorModeA,
   textClipPath = NULL;
   transpGroupStack = NULL;
   nestCount = 0;
+  xref = NULL;
 }
 
 void SplashOutputDev::setupScreenParams(double hDPI, double vDPI) {
@@ -1333,12 +1334,13 @@ void SplashOutputDev::startDoc(PDFDoc *docA) {
   nT3Fonts = 0;
 }
 
-void SplashOutputDev::startPage(int pageNum, GfxState *state) {
+void SplashOutputDev::startPage(int pageNum, GfxState *state, XRef *xrefA) {
   int w, h;
   double *ctm;
   SplashCoord mat[6];
   SplashColor color;
 
+  xref = xrefA;
   if (state) {
     setupScreenParams(state->getHDPI(), state->getVDPI());
     w = (int)(state->getPageWidth() + 0.5);
@@ -1790,7 +1792,7 @@ void SplashOutputDev::doUpdateFont(GfxState *state) {
 
   } else {
 
-    if (!(fontLoc = gfxFont->locateFont(doc->getXRef(), gFalse))) {
+    if (!(fontLoc = gfxFont->locateFont((xref) ? xref : doc->getXRef(), gFalse))) {
       error(errSyntaxError, -1, "Couldn't find a font for '{0:s}'",
 	    gfxFont->getName() ? gfxFont->getName()->getCString()
 	                       : "(unnamed)");
@@ -1800,7 +1802,7 @@ void SplashOutputDev::doUpdateFont(GfxState *state) {
     // embedded font
     if (fontLoc->locType == gfxFontLocEmbedded) {
       // if there is an embedded font, read it to memory
-      tmpBuf = gfxFont->readEmbFontFile(doc->getXRef(), &tmpBufLen);
+      tmpBuf = gfxFont->readEmbFontFile((xref) ? xref : doc->getXRef(), &tmpBufLen);
       if (! tmpBuf)
 	goto err2;
 
@@ -3270,7 +3272,7 @@ void SplashOutputDev::drawMaskedImage(GfxState *state, Object *ref,
   if (maskWidth > width || maskHeight > height) {
     decodeLow.initInt(maskInvert ? 0 : 1);
     decodeHigh.initInt(maskInvert ? 1 : 0);
-    maskDecode.initArray(doc->getXRef());
+    maskDecode.initArray((xref) ? xref : doc->getXRef());
     maskDecode.arrayAdd(&decodeLow);
     maskDecode.arrayAdd(&decodeHigh);
     maskColorMap = new GfxImageColorMap(1, &maskDecode,
diff --git a/poppler/SplashOutputDev.h b/poppler/SplashOutputDev.h
index f1c87ec..085b7a0 100644
--- a/poppler/SplashOutputDev.h
+++ b/poppler/SplashOutputDev.h
@@ -195,7 +195,7 @@ public:
   //----- initialization and control
 
   // Start a page.
-  virtual void startPage(int pageNum, GfxState *state);
+  virtual void startPage(int pageNum, GfxState *state, XRef *xref);
 
   // End a page.
   virtual void endPage();
@@ -396,6 +396,7 @@ private:
   GBool skipRotatedText;
 
   PDFDoc *doc;			// the current document
+  XRef *xref;       // the xref of the current document
 
   SplashBitmap *bitmap;
   Splash *splash;
diff --git a/poppler/Stream.cc b/poppler/Stream.cc
index 4ce6c00..f0d4602 100644
--- a/poppler/Stream.cc
+++ b/poppler/Stream.cc
@@ -38,6 +38,9 @@
 #endif
 
 #include <stdio.h>
+#ifdef _WIN32
+#include <io.h>
+#endif
 #include <stdlib.h>
 #include <stddef.h>
 #include <limits.h>
@@ -724,13 +727,30 @@ GBool StreamPredictor::getNextLine() {
 }
 
 //------------------------------------------------------------------------
+// UniqueFileStream
+//------------------------------------------------------------------------
+
+UniqueFileStream::UniqueFileStream(FILE *fA, char *fileNameA, Guint startA, GBool limitedA,
+		       Guint lengthA, Object *dictA):
+    FileStream(fA, fileNameA, startA, limitedA, lengthA, dictA) {
+  f = fopen(fileName, "rb");
+  reset();
+}
+
+UniqueFileStream::~UniqueFileStream() {
+  close();
+  fclose(f);
+}
+
+//------------------------------------------------------------------------
 // FileStream
 //------------------------------------------------------------------------
 
-FileStream::FileStream(FILE *fA, Guint startA, GBool limitedA,
+FileStream::FileStream(FILE *fA, char *fileNameA, Guint startA, GBool limitedA,
 		       Guint lengthA, Object *dictA):
     BaseStream(dictA, lengthA) {
   f = fA;
+  fileName = fileNameA;
   start = startA;
   limited = limitedA;
   length = lengthA;
@@ -744,9 +764,13 @@ FileStream::~FileStream() {
   close();
 }
 
+BaseStream *FileStream::copy() {
+  return new UniqueFileStream(f, fileName, start, limited, length, &dict);
+}
+
 Stream *FileStream::makeSubStream(Guint startA, GBool limitedA,
 				  Guint lengthA, Object *dictA) {
-  return new FileStream(f, startA, limitedA, lengthA, dictA);
+  return new UniqueFileStream(f, fileName, startA, limitedA, lengthA, dictA);
 }
 
 void FileStream::reset() {
@@ -868,6 +892,11 @@ CachedFileStream::~CachedFileStream()
   cc->decRefCnt();
 }
 
+BaseStream *CachedFileStream::copy() {
+  cc->incRefCnt();
+  return new CachedFileStream(cc, start, limited, length, &dict);
+}
+
 Stream *CachedFileStream::makeSubStream(Guint startA, GBool limitedA,
         Guint lengthA, Object *dictA)
 {
@@ -963,6 +992,10 @@ MemStream::~MemStream() {
   }
 }
 
+BaseStream *MemStream::copy() {
+  return new MemStream(buf, start, length, &dict);
+}
+
 Stream *MemStream::makeSubStream(Guint startA, GBool limited,
 				 Guint lengthA, Object *dictA) {
   MemStream *subStr;
@@ -1037,6 +1070,11 @@ EmbedStream::EmbedStream(Stream *strA, Object *dictA,
 EmbedStream::~EmbedStream() {
 }
 
+BaseStream *EmbedStream::copy() {
+  error(errInternal, -1, "Called copy() on EmbedStream");
+  return NULL;
+}
+
 Stream *EmbedStream::makeSubStream(Guint start, GBool limitedA,
 				   Guint lengthA, Object *dictA) {
   error(errInternal, -1, "Called makeSubStream() on EmbedStream");
diff --git a/poppler/Stream.h b/poppler/Stream.h
index a270fdf..173cdf2 100644
--- a/poppler/Stream.h
+++ b/poppler/Stream.h
@@ -298,6 +298,7 @@ public:
 
   BaseStream(Object *dictA, Guint lengthA);
   virtual ~BaseStream();
+  virtual BaseStream *copy() = 0;
   virtual Stream *makeSubStream(Guint start, GBool limited,
 				Guint length, Object *dict) = 0;
   virtual void setPos(Guint pos, int dir = 0) = 0;
@@ -315,9 +316,6 @@ public:
 protected:
 
   Guint length;
-
-private:
-
   Object dict;
 };
 
@@ -438,9 +436,10 @@ private:
 class FileStream: public BaseStream {
 public:
 
-  FileStream(FILE *fA, Guint startA, GBool limitedA,
+  FileStream(FILE *fA, char *fileName, Guint startA, GBool limitedA,
 	     Guint lengthA, Object *dictA);
   virtual ~FileStream();
+  virtual BaseStream *copy();
   virtual Stream *makeSubStream(Guint startA, GBool limitedA,
 				Guint lengthA, Object *dictA);
   virtual StreamKind getKind() { return strFile; }
@@ -485,7 +484,10 @@ private:
       return n;
     }
 
+protected:
   FILE *f;
+  char *fileName;
+private:
   Guint start;
   GBool limited;
   char buf[fileStreamBufSize];
@@ -496,6 +498,14 @@ private:
   GBool saved;
 };
 
+class UniqueFileStream: public FileStream {
+public:
+
+  UniqueFileStream(FILE *fA, char *fileNameA, Guint startA, GBool limitedA,
+	     Guint lengthA, Object *dictA);
+  virtual ~UniqueFileStream();
+};
+
 //------------------------------------------------------------------------
 // CachedFileStream
 //------------------------------------------------------------------------
@@ -508,6 +518,7 @@ public:
   CachedFileStream(CachedFile *ccA, Guint startA, GBool limitedA,
 	     Guint lengthA, Object *dictA);
   virtual ~CachedFileStream();
+  virtual BaseStream *copy();
   virtual Stream *makeSubStream(Guint startA, GBool limitedA,
 				Guint lengthA, Object *dictA);
   virtual StreamKind getKind() { return strCachedFile; }
@@ -550,6 +561,7 @@ public:
 
   MemStream(char *bufA, Guint startA, Guint lengthA, Object *dictA);
   virtual ~MemStream();
+  virtual BaseStream *copy();
   virtual Stream *makeSubStream(Guint start, GBool limited,
 				Guint lengthA, Object *dictA);
   virtual StreamKind getKind() { return strWeird; }
@@ -598,6 +610,7 @@ public:
 
   EmbedStream(Stream *strA, Object *dictA, GBool limitedA, Guint lengthA);
   virtual ~EmbedStream();
+  virtual BaseStream *copy();
   virtual Stream *makeSubStream(Guint start, GBool limitedA,
 				Guint lengthA, Object *dictA);
   virtual StreamKind getKind() { return str->getKind(); }
diff --git a/poppler/TextOutputDev.cc b/poppler/TextOutputDev.cc
index 9af7532..3637be2 100644
--- a/poppler/TextOutputDev.cc
+++ b/poppler/TextOutputDev.cc
@@ -4296,7 +4296,7 @@ TextSelectionPainter::TextSelectionPainter(TextPage *page,
 
   state = new GfxState(72 * scale, 72 * scale, &box, rotation, gFalse);
 
-  out->startPage (0, state);
+  out->startPage (0, state, NULL);
   out->setDefaultCTM (state->getCTM());
 
   state->setTextMat(1, 0, 0, -1, 0, 0);
@@ -5362,7 +5362,7 @@ TextOutputDev::~TextOutputDev() {
   delete actualText;
 }
 
-void TextOutputDev::startPage(int pageNum, GfxState *state) {
+void TextOutputDev::startPage(int pageNum, GfxState *state, XRef *xref) {
   text->startPage(state);
 }
 
diff --git a/poppler/TextOutputDev.h b/poppler/TextOutputDev.h
index e31876b..0b871a3 100644
--- a/poppler/TextOutputDev.h
+++ b/poppler/TextOutputDev.h
@@ -717,7 +717,7 @@ public:
   //----- initialization and control
 
   // Start a page.
-  virtual void startPage(int pageNum, GfxState *state);
+  virtual void startPage(int pageNum, GfxState *state, XRef *xref);
 
   // End a page.
   virtual void endPage();
diff --git a/poppler/XRef.cc b/poppler/XRef.cc
index 3564807..6093379 100644
--- a/poppler/XRef.cc
+++ b/poppler/XRef.cc
@@ -65,6 +65,14 @@
 #define permHighResPrint  (1<<11) // bit 12
 #define defPermFlags 0xfffc
 
+#if MULTITHREADED
+#  define lockXRef   gLockMutex(&mutex)
+#  define unlockXRef gUnlockMutex(&mutex)
+#else
+#  define lockXRef
+#  define unlockXRef
+#endif
+
 //------------------------------------------------------------------------
 // ObjectStream
 //------------------------------------------------------------------------
@@ -257,6 +265,9 @@ Object *ObjectStream::getObject(int objIdx, int objNum, Object *obj) {
 //------------------------------------------------------------------------
 
 void XRef::init() {
+#if MULTITHREADED
+  gInitMutex(&mutex);
+#endif
   ok = gTrue;
   errCode = errNone;
   entries = NULL;
@@ -267,6 +278,7 @@ void XRef::init() {
   objStrs = new PopplerCache(5);
   mainXRefEntriesOffset = 0;
   xRefStream = gFalse;
+  strOwner = gFalse;
 }
 
 XRef::XRef() {
@@ -373,6 +385,38 @@ XRef::~XRef() {
   if (objStrs) {
     delete objStrs;
   }
+  if (strOwner)
+    delete str;
+}
+
+XRef *XRef::copy() {
+  lockXRef;
+  XRef *xref = new XRef();
+  xref->str = str->copy();
+  xref->strOwner = gTrue;
+  xref->encrypted = encrypted;
+  xref->permFlags = permFlags;
+  xref->ownerPasswordOk = ownerPasswordOk;
+
+  xref->start = start;
+  xref->prevXRefOffset = prevXRefOffset;
+  xref->trailerDict.initDict(trailerDict.getDict());
+  xref->encAlgorithm = encAlgorithm;
+  xref->encRevision = encRevision;
+  xref->encVersion = encVersion;
+  xref->permFlags = permFlags;
+
+  xref->reserve(size);
+  xref->size = size;
+  for (int i = 0; i < size; ++i) {
+    xref->entries[i].offset = entries[i].offset;
+    xref->entries[i].type = entries[i].type;
+    xref->entries[i].obj.initNull ();
+    xref->entries[i].updated = entries[i].updated;
+    xref->entries[i].gen = entries[i].gen;
+  }
+  unlockXRef;
+  return xref;
 }
 
 int XRef::reserve(int newSize)
@@ -1001,7 +1045,7 @@ Object *XRef::fetch(int num, int gen, Object *obj, int recursion) {
     obj = e->obj.copy(obj);
     return obj;
   }
-
+ 
   switch (e->type) {
 
   case xrefEntryUncompressed:
@@ -1415,7 +1459,7 @@ XRefEntry *XRef::getEntry(int i, GBool complainIfMissing)
            break;
         }
       }
-      
+   
       // We might have reconstructed the xref
       // Check again i is in bounds
       if (unlikely(i >= size)) {
diff --git a/poppler/XRef.h b/poppler/XRef.h
index 148a5ce..ee911ef 100644
--- a/poppler/XRef.h
+++ b/poppler/XRef.h
@@ -36,6 +36,7 @@
 
 #include "goo/gtypes.h"
 #include "Object.h"
+#include "goo/GooMutex.h"
 
 #include <vector>
 
@@ -76,6 +77,9 @@ public:
   // Destructor.
   ~XRef();
 
+  // Copy xref but with new base stream!
+  XRef *copy();
+
   // Is xref table valid?
   GBool isOk() { return ok; }
 
@@ -171,6 +175,7 @@ private:
   Guint prevXRefOffset;		// position of prev XRef section (= next to read)
   Guint mainXRefEntriesOffset;	// offset of entries in main XRef table
   GBool xRefStream;		// true if last XRef section is a stream
+  GBool strOwner;     // true if str is owned by the instance
 
   void init();
   int reserve(int newSize);
@@ -210,6 +215,9 @@ private:
   };
 
   void writeXRef(XRefWriter *writer, GBool writeAllEntries);
+#if MULTITHREADED
+  GooMutex mutex;
+#endif
 };
 
 #endif
diff --git a/utils/HtmlOutputDev.cc b/utils/HtmlOutputDev.cc
index 83f65d5..441184b 100644
--- a/utils/HtmlOutputDev.cc
+++ b/utils/HtmlOutputDev.cc
@@ -1236,7 +1236,7 @@ HtmlOutputDev::~HtmlOutputDev() {
       delete pages;
 }
 
-void HtmlOutputDev::startPage(int pageNum, GfxState *state) {
+void HtmlOutputDev::startPage(int pageNum, GfxState *state, XRef *xref) {
 #if 0
   if (mode&&!xml){
     if (write){
diff --git a/utils/HtmlOutputDev.h b/utils/HtmlOutputDev.h
index 12b16bf..d8d2870 100644
--- a/utils/HtmlOutputDev.h
+++ b/utils/HtmlOutputDev.h
@@ -279,7 +279,7 @@ public:
 
 
   // Start a page.
-  virtual void startPage(int pageNum, GfxState *state);
+  virtual void startPage(int pageNum, GfxState *state, XRef *xref);
 
   // End a page.
   virtual void endPage();
diff --git a/utils/ImageOutputDev.h b/utils/ImageOutputDev.h
index 6201a24..51e4645 100644
--- a/utils/ImageOutputDev.h
+++ b/utils/ImageOutputDev.h
@@ -78,7 +78,7 @@ public:
   virtual GBool needNonText() { return gTrue; }
 
   // Start a page
-  virtual void startPage(int pageNumA, GfxState *state) 
+  virtual void startPage(int pageNumA, GfxState *state, XRef *xref) 
 			{ pageNum = pageNumA; }
  
   //---- get info about output device