Preserve input PDF version on pages/split-pages (fixes #610)

ChangeLog

@@ -1,11 +1,22 @@
 2022-02-08  Jay Berkenbilt  <ejb@ql.org>
 
+	* Bug fix: when splitting pages with --split-pages or selecting
+	pages with --pages, set the output PDF version to the maximum of
+	all the input PDF versions. This is a fix to QPDFJob. If you are
+	creating output PDF files yourself from multiple inputs, you will
+	need to code the same thing. The new PDFVersion object, its
+	updateIfGreater() method, and the new QPDF and QPDFWriter methods
+	described below make this very easy to do. Fixes #610.
+
 	* Add new class PDFVersion for more convenient comparison of PDF
 	version numbers from the %!PDF header.
 
 	* Add QPDF::getVersionAsPDFVersion() to return the PDF version and
 	extension together as a PDFVersion object instead of a string.
 
+	* Add a QPDFWriter::setMinimumPDFVersion() that takes a PDFVersion
+	object.
+
 2022-02-06  Jay Berkenbilt  <ejb@ql.org>
 
 	* Pl_Buffer and QPDFWriter: add getBufferSharedPointer(), which

TODO

@@ -1,8 +1,3 @@
-10.6
-====
-
-* https://github.com/qpdf/qpdf/issues/610
-
 Next
 ====
 

include/qpdf/QPDFJob.hh

@@ -26,6 +26,7 @@
 #include <qpdf/Constants.h>
 #include <qpdf/QPDF.hh>
 #include <qpdf/QPDFPageObjectHelper.hh>
+#include <qpdf/PDFVersion.hh>
 
 #include <memory>
 #include <string>
@@ -587,6 +588,7 @@ class QPDFJob
         int flatten_annotations_required;
         int flatten_annotations_forbidden;
         bool generate_appearances;
+        PDFVersion max_input_version;
         std::string min_version;
         std::string force_version;
         bool show_npages;

include/qpdf/QPDFWriter.hh

@@ -42,11 +42,11 @@
 #include <qpdf/QPDFObjectHandle.hh>
 #include <qpdf/QPDFObjGen.hh>
 #include <qpdf/QPDFXRefEntry.hh>
-
 #include <qpdf/Pl_Buffer.hh>
 #include <qpdf/PointerHolder.hh>
 #include <qpdf/Pipeline.hh>
 #include <qpdf/Buffer.hh>
+#include <qpdf/PDFVersion.hh>
 
 class QPDF;
 class Pl_Count;
@@ -265,6 +265,8 @@ class QPDFWriter
     // streams are used.
     QPDF_DLL
     void setMinimumPDFVersion(std::string const&, int extension_level = 0);
+    QPDF_DLL
+    void setMinimumPDFVersion(PDFVersion const&);
 
     // Force the PDF version of the output file to be a given version.
     // Use of this function may create PDF files that will not work

libqpdf/QPDFJob.cc

@@ -2047,6 +2047,7 @@ QPDFJob::doProcessOnce(
     {
         fn(pdf.get(), password);
     }
+    this->m->max_input_version.updateIfGreater(pdf->getVersionAsPDFVersion());
     return pdf;
 }
 
@@ -3472,6 +3473,7 @@ QPDFJob::setWriterOptions(QPDF& pdf, QPDFWriter& w)
     {
         w.setObjectStreamMode(m->object_stream_mode);
     }
+    w.setMinimumPDFVersion(this->m->max_input_version);
     if (! m->min_version.empty())
     {
         std::string version;

libqpdf/QPDFWriter.cc

@@ -296,6 +296,15 @@ QPDFWriter::setMinimumPDFVersion(std::string const& version,
     }
 }
 
+void
+QPDFWriter::setMinimumPDFVersion(PDFVersion const& v)
+{
+    std::string version;
+    int extension_level;
+    v.getVersion(version, extension_level);
+    setMinimumPDFVersion(version, extension_level);
+}
+
 void
 QPDFWriter::forcePDFVersion(std::string const& version,
                             int extension_level)

manual/release-notes.rst

@@ -148,6 +148,14 @@ For a detailed list of changes, please see the file
       embedded NUL characters. Thanks to M. Holger for the
       contribution.
 
+    - New ``PDFVersion`` class for representing a PDF version number
+      with the ability to compare and order PDF versions. Methods
+      ``QPDF::getVersionAsPDFVersion`` and a new version of
+      ``QPDFWriter::setMinimumPDFVersion`` use it. This makes it
+      easier to create an output file whose PDF version is the maximum
+      of the versions across all the input files that contributed to
+      it.
+
     - The ``JSON`` object in the qpdf library has been enhanced to
       include a parser and the ability to get values out of the
       ``JSON`` object. Previously it was a write-only interface. Even
@@ -181,6 +189,10 @@ For a detailed list of changes, please see the file
     - Some characters were not correctly translated from PDF doc
       encoding to Unicode.
 
+    - When splitting or combining pages, ensure that all output files
+      have a PDF version greater than or equal to the maximum version
+      of all the input files.
+
 10.5.0: December 21, 2021
   - Packaging changes
 

qpdf/qtest/qpdf/direct-dr-out.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.6
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/dr-with-indirect-item-out.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %¿÷¢þ
 1 0 obj
 << /AcroForm 2 0 R /Pages 3 0 R /Type /Catalog >>

qpdf/qtest/qpdf/indirect-r-arg.out

@@ -1,7 +1,7 @@
-checking indirect-r-arg.pdf
 WARNING: indirect-r-arg.pdf (object 1 0, offset 76): unknown token while reading object; treating as string
 WARNING: indirect-r-arg.pdf (object 1 0, offset 62): expected dictionary key but found non-name object; inserting key /QPDFFake1
 WARNING: indirect-r-arg.pdf (object 1 0, offset 62): expected dictionary key but found non-name object; inserting key /QPDFFake2
+checking indirect-r-arg.pdf
 PDF Version: 1.3
 File is not encrypted
 File is not linearized

qpdf/qtest/qpdf/labels-split-01-06.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/labels-split-07-11.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/merge-implicit-ranges.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %¿÷¢þ
 1 0 obj
 << /PageLabels << /Nums [ 0 << /St 1 >> 21 << /P () /St 1 >> 23 << /S /r /St 1 >> 28 << /P () /St 1 >> 30 << /S /r /St 6 >> 32 << /P () /St 1 >> 33 << /S /D /St 2 >> 36 << /S /D /St 6 >> 40 << /P () /St 1 >> 41 << /S /D /St 12 >> 43 << /S /D /St 16059 >> 44 << /S /r /St 50 >> 50 << /S /r /St 54 >> ] >> /Pages 2 0 R /Type /Catalog >>

qpdf/qtest/qpdf/obj0-check.out

@@ -1,7 +1,7 @@
-checking obj0.pdf
 WARNING: obj0.pdf: file is damaged
 WARNING: obj0.pdf (object 1 0, offset 77): expected n n obj
 WARNING: obj0.pdf: Attempting to reconstruct cross-reference table
+checking obj0.pdf
 PDF Version: 1.3
 File is not encrypted
 File is not linearized

qpdf/qtest/qpdf/overlay-copy-annotations-p1.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.6
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/overlay-copy-annotations-p2.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.6
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/overlay-copy-annotations-p5.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.6
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/overlay-copy-annotations-p6.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.6
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/overlay-copy-annotations.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.6
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_01

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_02

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_03

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_04

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_05

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_06

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_07

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_08

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_09

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_10

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/split-exp.zdf_11

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0
 

qpdf/qtest/qpdf/uo-7.pdf

@@ -1,4 +1,4 @@
-%PDF-1.3
+%PDF-1.4
 %©В╒Ч
 %QDF-1.0