[tex-k] libpoppler support in TeX Live source tree

Tue May 5 23:22:32 CEST 2009

Hi Nobert,

many thanks for your work on this.

On Tue, May 05, 2009 at 03:55:42PM +0200, Norbert Preining wrote:
> On Di, 05 Mai 2009, Norbert Preining wrote:
> > 	objectStream *objStr = xref->getObjStr();
> > in texk/web2c/pdftexdir/pdftosrc.cc:167 does not compile with poppler,
> > warning is:
> > ../../../texk/web2c/pdftexdir/pdftosrc.cc:167: error: ‘class XRef’ has no member named ‘getObjStr’
> > ../../../texk/web2c/pdftexdir/pdftosrc.cc:169: error: invalid use of incomplete type ‘struct ObjectStream’
> > /usr/include/poppler/XRef.h:39: error: forward declaration of ‘struct ObjectStream’
> > ../../../texk/web2c/pdftexdir/pdftosrc.cc:174: error: invalid use of incomplete type ‘struct ObjectStream’
> > /usr/include/poppler/XRef.h:39: error: forward declaration of ‘struct ObjectStream’
> 
> 
> Ok, googling found one hit, and that is a patch from redhat for poppler
> 0.6.2 that seems to not have been included:
> 
> It moves the declaration of ObjectStream form XRef.cc to XRef.h and
> defines getObjStr.
> https://www.redhat.com/archives/fedora-extras-commits/2007-November/msg08712.html

this sounds very similar to a patch I made to xpdf, to
support object stream for pdftosrc. Below I copied the
relevant text I sent in a previous mail to Peter and others.

I suggested to remove support for object stream from
pdftosrc (or remove pdftosrc), so that we can get rid of
this patch. But Peter and Karl don't think it's a good idea.
So we need to maintain this patch for both xpdf and poppler
it seems.

Another workaround is to maintain a separate tree for
pdftosrc; this patch would be applied to a (temporary)
XRef.cc & XRef.h during compilation of pdftosrc. Sounds a
bit awkward, but IMO better than changing the original
XRef.{cc,h}.

Regards,
Thanh

,--------
| diff -ur xpdf-3.02.orig/xpdf/XRef.cc xpdf-3.02/xpdf/XRef.cc
| --- xpdf-3.02.orig/xpdf/XRef.cc       2007-02-27 23:05:52.000000000 +0100
| +++ xpdf-3.02/xpdf/XRef.cc    2008-05-08 15:40:41.000000000 +0200
| @@ -45,34 +96,9 @@
|  // ObjectStream
|  //------------------------------------------------------------------------
|
| -class ObjectStream {
| -public:
| -
| -  // Create an object stream, using object number <objStrNum>,
| -  // generation 0.
| -  ObjectStream(XRef *xref, int objStrNumA);
| -
| -  ~ObjectStream();
| -
| -  // Return the object number of this object stream.
| -  int getObjStrNum() { return objStrNum; }
| -
| -  // Get the <objIdx>th object from this stream, which should be
| -  // object number <objNum>, generation 0.
| -  Object *getObject(int objIdx, int objNum, Object *obj);
| -
| -private:
| -
| -  int objStrNum;             // object number of the object stream
| -  int nObjects;                      // number of objects in the stream
| -  Object *objs;                      // the objects (length = nObjects)
| -  int *objNums;                      // the object numbers (length = nObjects)
| -};
| -
|  ObjectStream::ObjectStream(XRef *xref, int objStrNumA) {
|    Stream *str;
|    Parser *parser;
| -  int *offsets;
|    Object objStr, obj1, obj2;
|    int first, i;
|
| @@ -80,6 +106,7 @@
|    nObjects = 0;
|    objs = NULL;
|    objNums = NULL;
| +  offsets = NULL;
|
|    if (!xref->fetch(objStrNum, 0, &objStr)->isStream()) {
|      goto err1;
| @@ -100,6 +127,7 @@
|      goto err1;
|    }
|    first = obj1.getInt();
| +  firstOffset = objStr.getStream()->getBaseStream()->getStart() + first;
|    obj1.free();
|    if (first < 0) {
|      goto err1;
| @@ -121,7 +149,7 @@
|        obj1.free();
|        obj2.free();
|        delete parser;
| -      gfree(offsets);
| +//       gfree(offsets);
|        goto err1;
|      }
|      objNums[i] = obj1.getInt();
| @@ -131,7 +159,7 @@
|      if (objNums[i] < 0 || offsets[i] < 0 ||
|       (i > 0 && offsets[i] < offsets[i-1])) {
|        delete parser;
| -      gfree(offsets);
| +//       gfree(offsets);
|        goto err1;
|      }
|    }
| @@ -160,7 +188,7 @@
|      delete parser;
|    }
|
| -  gfree(offsets);
| +//   gfree(offsets);
|
|   err1:
|    objStr.free();
| @@ -177,6 +205,7 @@
|      delete[] objs;
|    }
|    gfree(objNums);
| +  gfree(offsets);
|  }
|
|  Object *ObjectStream::getObject(int objIdx, int objNum, Object *obj) {
| diff -ur xpdf-3.02.orig/xpdf/XRef.h xpdf-3.02/xpdf/XRef.h
| --- xpdf-3.02.orig/xpdf/XRef.h        2007-02-27 23:05:52.000000000 +0100
| +++ xpdf-3.02/xpdf/XRef.h     2008-05-08 15:40:41.000000000 +0200
| @@ -21,7 +60,36 @@
|  class Dict;
|  class Stream;
|  class Parser;
| -class ObjectStream;
| +
| +class ObjectStream {
| +public:
| +
| +  // Create an object stream, using object number <objStrNum>,
| +  // generation 0.
| +  ObjectStream(XRef *xref, int objStrNumA);
| +
| +  ~ObjectStream();
| +
| +  // Return the object number of this object stream.
| +  int getObjStrNum() { return objStrNum; }
| +
| +  // Get the <objIdx>th object from this stream, which should be
| +  // object number <objNum>, generation 0.
| +  Object *getObject(int objIdx, int objNum, Object *obj);
| +
| +  int *getOffsets() { return offsets; }
| +  Guint getFirstOffset() { return firstOffset; }
| +
| +private:
| +
| +  int objStrNum;             // object number of the object stream
| +  int nObjects;                      // number of objects in the stream
| +  Object *objs;                      // the objects (length = nObjects)
| +  int *objNums;                      // the object numbers (length = nObjects)
| +  int *offsets;                      // the object offsets (length = nObjects)
| +  Guint firstOffset;
| +};
| +
|
|  //------------------------------------------------------------------------
|  // XRef
| @@ -96,6 +164,7 @@
|    int getSize() { return size; }
|    XRefEntry *getEntry(int i) { return &entries[i]; }
|    Object *getTrailerDict() { return &trailerDict; }
| +  ObjectStream *getObjStr() { return objStr; }
|
|  private:
`--------

Thanh's comment: Took me a while before I could recall where
it comes from. This is the relevant mail I sent to Derek
some time ago:

This change is "nice-to-have", but not a critical one.