Fix nullpointer for transform functions in separation

Type 0 and Type 4 functions pass a PdfStream and not a PdfDictionnary
Separation CS can contain a function, which can be a stream as well
Add tests

DEVSIX-1663

Author: Samuel Huylebroeck

pdfa/src/main/java/com/itextpdf/pdfa/PdfAConformanceException.java

@@ -146,7 +146,11 @@ public class PdfAConformanceException extends PdfException {
     public static final String TheSmaskKeyIsNotAllowedInXobjects = "The smask key is not allowed in xobjects";
     public static final String TheValueOfInterpolateKeyShallNotBeTrue = "The value of interpolate key shall not be true";
     public static final String TheValueOfTheMethEntryInColrBoxShallBe123 = "The value of the meth entry in colr box shall be 123";
+    //TODO(DEVSIX-1672): remove in 7.1
+    @Deprecated
     public static final String TintTransformAndAlternateSpaceOfSeparationArraysInTheColorantsOfDeviceNShallBeConsistentWithSameAttributesOfDeviceN = "TintTransform and alternateSpace of separation arrays in the colorants of deviceN shall be consistent with same attributes of deviceN";
+    //TODO(DEVSIX-1672): move to LogConstants
+    public static final String WarningTintTransformAndAlternateSpaceOfSeparationArraysInTheColorantsOfDeviceNShallBeConsistentWithSameAttributesOfDeviceN = "WARNING: TintTransform and alternateSpace of separation arrays in the colorants of deviceN is not consistent with same attributes of deviceN";
     public static final String TintTransformAndAlternateSpaceShallBeTheSameForTheAllSeparationCSWithTheSameName = "TintTransform and alternateSpace shall be the same for the all separation cs with the same name";
     public static final String TransparencyIsNotAllowedCAShallBeEqualTo1 = "Transparency is not allowed. CA shall be equal to 1";
     public static final String TransparencyIsNotAllowedCaShallBeEqualTo1 = "Transparency is not allowed. ca shall be equal to 1";

pdfa/src/main/java/com/itextpdf/pdfa/checker/PdfA2Checker.java

@@ -70,6 +70,8 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.extgstate.PdfExtGState;
 import com.itextpdf.pdfa.PdfAConformanceException;
 import com.itextpdf.kernel.pdf.PdfAConformanceLevel;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -107,6 +109,8 @@ public class PdfA2Checker extends PdfA1Checker {
 
     private Map<PdfName, PdfArray> separationColorSpaces = new HashMap<>();
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(PdfA2Checker.class);
+
 
     /**
      * Creates a PdfA2Checker with the required conformance level
@@ -188,7 +192,7 @@ public void checkColorSpace(PdfColorSpace colorSpace, PdfDictionary currentColor
             if (colorants != null) {
                 for (Map.Entry<PdfName, PdfObject> entry : colorants.entrySet()) {
                     PdfArray separation = (PdfArray) entry.getValue();
-                    checkSeparationInsideDeviceN(separation, ((PdfArray) deviceN.getPdfObject()).get(2), ((PdfArray) deviceN.getPdfObject()).get(3).getIndirectReference());
+                    checkSeparationInsideDeviceN(separation, ((PdfArray) deviceN.getPdfObject()).get(2), ((PdfArray) deviceN.getPdfObject()).get(3));
                 }
             }
             if (checkAlternate) {
@@ -817,29 +821,34 @@ private void checkBlendMode(PdfName blendMode) {
         }
     }
 
-    private void checkSeparationInsideDeviceN(PdfArray separation, PdfObject deviceNColorSpace, PdfIndirectReference deviceNTintTransform) {
+    private void checkSeparationInsideDeviceN(PdfArray separation, PdfObject deviceNColorSpace, PdfObject deviceNTintTransform) {
         if (!isAltCSIsTheSame(separation.get(2), deviceNColorSpace) ||
-                !deviceNTintTransform.equals(separation.getAsDictionary(3).getIndirectReference())) {
-            throw new PdfAConformanceException(PdfAConformanceException.TintTransformAndAlternateSpaceOfSeparationArraysInTheColorantsOfDeviceNShallBeConsistentWithSameAttributesOfDeviceN);
+                !deviceNTintTransform.equals(separation.get(3))) {
+            LOGGER.warn(PdfAConformanceException.WarningTintTransformAndAlternateSpaceOfSeparationArraysInTheColorantsOfDeviceNShallBeConsistentWithSameAttributesOfDeviceN);
         }
 
         checkSeparationCS(separation);
     }
 
     private void checkSeparationCS(PdfArray separation) {
         if (separationColorSpaces.containsKey(separation.getAsName(0))) {
-            boolean altCSIsTheSame = false;
-            boolean tintTransformIsTheSame = false;
+            boolean altCSIsTheSame;
+            boolean tintTransformIsTheSame;
 
             PdfArray sameNameSeparation = separationColorSpaces.get(separation.getAsName(0));
             PdfObject cs1 = separation.get(2);
             PdfObject cs2 = sameNameSeparation.get(2);
             altCSIsTheSame = isAltCSIsTheSame(cs1, cs2);
+            // TODO(DEVSIX-1672) in fact need to check if objects content is equal. ISO 19005-2, 6.2.4.4 "Separation and DeviceN colour spaces":
+            // In evaluating equivalence, the PDF objects shall be compared, rather than the computational
+            // result of the use of those PDF objects. Compression and whether or not an object is direct or indirect shall be ignored.
+            PdfObject f1Obj = separation.get(3);
+            PdfObject f2Obj = sameNameSeparation.get(3);
+            //Can be a stream or dict
+            boolean bothAllowedType = (f1Obj.getType() == f2Obj.getType()) && (f1Obj.isDictionary() || f1Obj.isStream());
+            //Check if the indirect references are equal
+            tintTransformIsTheSame = bothAllowedType && f1Obj.equals(f2Obj);
 
-            PdfDictionary f1 = separation.getAsDictionary(3);
-            PdfDictionary f2 = sameNameSeparation.getAsDictionary(3);
-            //todo compare dictionaries or stream references
-            tintTransformIsTheSame = f1.getIndirectReference().equals(f2.getIndirectReference());
 
             if (!altCSIsTheSame || !tintTransformIsTheSame) {
                 throw new PdfAConformanceException(PdfAConformanceException.TintTransformAndAlternateSpaceShallBeTheSameForTheAllSeparationCSWithTheSameName);
@@ -855,7 +864,9 @@ private boolean isAltCSIsTheSame(PdfObject cs1, PdfObject cs2) {
         if (cs1 instanceof PdfName) {
             altCSIsTheSame = cs1.equals(cs2);
         } else if (cs1 instanceof PdfArray && cs2 instanceof PdfArray) {
-            //todo compare cs dictionaries or stream reference
+            // TODO(DEVSIX-1672) in fact need to check if objects content is equal. ISO 19005-2, 6.2.4.4 "Separation and DeviceN colour spaces":
+            // In evaluating equivalence, the PDF objects shall be compared, rather than the computational
+            // result of the use of those PDF objects. Compression and whether or not an object is direct or indirect shall be ignored.
             altCSIsTheSame = ((PdfArray) cs1).get(0).equals(((PdfArray) cs1).get(0));
         }
         return altCSIsTheSame;

pdfa/src/test/java/com/itextpdf/pdfa/PdfA2GraphicsCheckTest.java

@@ -47,18 +47,26 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.color.ColorConstants;
 import com.itextpdf.kernel.color.DeviceCmyk;
 import com.itextpdf.kernel.color.DeviceGray;
+import com.itextpdf.kernel.color.DeviceN;
+import com.itextpdf.kernel.color.Separation;
 import com.itextpdf.kernel.font.PdfFont;
 import com.itextpdf.kernel.font.PdfFontFactory;
 import com.itextpdf.kernel.pdf.PdfAConformanceLevel;
+import com.itextpdf.kernel.pdf.PdfArray;
 import com.itextpdf.kernel.pdf.PdfDictionary;
 import com.itextpdf.kernel.pdf.PdfName;
 import com.itextpdf.kernel.pdf.PdfNumber;
 import com.itextpdf.kernel.pdf.PdfOutputIntent;
+import com.itextpdf.kernel.pdf.PdfPage;
 import com.itextpdf.kernel.pdf.PdfWriter;
 import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
 import com.itextpdf.kernel.pdf.canvas.PdfCanvasConstants;
 import com.itextpdf.kernel.pdf.colorspace.PdfCieBasedCs;
+import com.itextpdf.kernel.pdf.colorspace.PdfColorSpace;
+import com.itextpdf.kernel.pdf.colorspace.PdfDeviceCs;
+import com.itextpdf.kernel.pdf.colorspace.PdfSpecialCs;
 import com.itextpdf.kernel.pdf.extgstate.PdfExtGState;
+import com.itextpdf.kernel.pdf.function.PdfFunction;
 import com.itextpdf.kernel.utils.CompareTool;
 import com.itextpdf.kernel.xmp.XMPException;
 import com.itextpdf.test.ExtendedITextTest;
@@ -75,6 +83,7 @@ This file is part of the iText (R) project.
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
+import java.util.Collections;
 
 import static org.junit.Assert.fail;
 
@@ -500,6 +509,82 @@ public void transparencyCheckTest3() throws FileNotFoundException, XMPException
         doc.close();
     }
 
+    @Test
+    public void colourSpaceTest01() throws FileNotFoundException {
+        PdfWriter writer = new PdfWriter(new com.itextpdf.io.source.ByteArrayOutputStream());
+        InputStream is = new FileInputStream(sourceFolder + "sRGB Color Space Profile.icm");
+        PdfADocument doc = new PdfADocument(writer, PdfAConformanceLevel.PDF_A_2B, new PdfOutputIntent("Custom", "", "http://www.color.org", "sRGB IEC61966-2.1", is));
+        PdfPage page = doc.addNewPage();
+
+        PdfColorSpace alternateSpace= new PdfDeviceCs.Rgb();
+        //Tint transformation function is a stream
+        byte[] samples = {0x00,0x00,0x00,0x01,0x01,0x01};
+        PdfArray domain = new PdfArray(new float[]{0,1});
+        PdfArray range  =new PdfArray(new float[]{0,1,0,1,0,1});
+        PdfArray size = new PdfArray(new float[]{2});
+        PdfNumber bitsPerSample = new PdfNumber(8);
+
+        PdfFunction.Type0 type0 = new PdfFunction.Type0(domain,range,size,bitsPerSample,samples);
+        PdfColorSpace separationColourSpace = new PdfSpecialCs.Separation("separationTestFunction0",alternateSpace,type0);
+        //Add to document
+        page.getResources().addColorSpace(separationColourSpace);
+
+        doc.close();
+    }
+
+    @Test
+    public void colourSpaceTest02() throws FileNotFoundException {
+        PdfWriter writer = new PdfWriter(new com.itextpdf.io.source.ByteArrayOutputStream());
+        InputStream is = new FileInputStream(sourceFolder + "sRGB Color Space Profile.icm");
+        PdfADocument doc = new PdfADocument(writer, PdfAConformanceLevel.PDF_A_2B, new PdfOutputIntent("Custom", "", "http://www.color.org", "sRGB IEC61966-2.1", is));
+        PdfPage page = doc.addNewPage();
+
+        PdfColorSpace alternateSpace= new PdfDeviceCs.Rgb();
+        //Tint transformation function is a dictionary
+        PdfArray domain = new PdfArray(new float[]{0,1});
+        PdfArray range  =new PdfArray(new float[]{0,1,0,1,0,1});
+        PdfArray C0 = new PdfArray(new float[]{0,0,0});
+        PdfArray C1 = new PdfArray(new float[]{1,1,1});
+        PdfNumber n = new PdfNumber(1);
+
+        PdfFunction.Type2 type2 = new PdfFunction.Type2(domain,range,C0,C1,n);
+        PdfColorSpace separationColourSpace = new PdfSpecialCs.Separation("separationTestFunction2",alternateSpace,type2);
+        //Add to document
+        page.getResources().addColorSpace(separationColourSpace);
+        doc.close();
+    }
+
+    @Test
+    public void colourSpaceTest03() throws FileNotFoundException {
+        PdfWriter writer = new PdfWriter(new com.itextpdf.io.source.ByteArrayOutputStream());
+        InputStream is = new FileInputStream(sourceFolder + "sRGB Color Space Profile.icm");
+        PdfADocument doc = new PdfADocument(writer, PdfAConformanceLevel.PDF_A_2B, new PdfOutputIntent("Custom", "", "http://www.color.org", "sRGB IEC61966-2.1", is));
+        PdfPage page = doc.addNewPage();
+
+        PdfColorSpace alternateSpace= new PdfDeviceCs.Rgb();
+        //Tint transformation function is a dictionary
+        PdfArray domain = new PdfArray(new float[]{0,1});
+        PdfArray range  =new PdfArray(new float[]{0,1,0,1,0,1});
+        PdfArray C0 = new PdfArray(new float[]{0,0,0});
+        PdfArray C1 = new PdfArray(new float[]{1,1,1});
+        PdfNumber n = new PdfNumber(1);
+
+        PdfFunction.Type2 type2 = new PdfFunction.Type2(domain,range,C0,C1,n);
+
+        PdfCanvas canvas = new PdfCanvas(page);
+        String separationName = "separationTest";
+        canvas.setColor(new Separation(separationName, alternateSpace, type2, 0.5f), true);
+
+        PdfDictionary attributes = new PdfDictionary();
+        PdfDictionary colorantsDict = new PdfDictionary();
+        colorantsDict.put(new PdfName(separationName), new PdfSpecialCs.Separation(separationName, alternateSpace,type2).getPdfObject());
+        attributes.put(PdfName.Colorants, colorantsDict);
+        DeviceN deviceN = new DeviceN(new PdfSpecialCs.NChannel(Collections.<String>singletonList(separationName), alternateSpace, type2, attributes), new float[]{0.5f});
+        canvas.setColor(deviceN, true);
+
+        doc.close();
+    }
+
     private void compareResult(String outPdf, String cmpPdf) throws IOException, InterruptedException {
         String result = new CompareTool().compareByContent(outPdf, cmpPdf, destinationFolder, "diff_");
         if (result != null) {

pdfa/src/test/java/com/itextpdf/pdfa/PdfA2PageCheckTest.java

@@ -43,19 +43,30 @@ This file is part of the iText (R) project.
 package com.itextpdf.pdfa;
 
 import com.itextpdf.io.source.ByteArrayOutputStream;
+import com.itextpdf.kernel.color.Color;
+import com.itextpdf.kernel.color.DeviceN;
+import com.itextpdf.kernel.color.Separation;
 import com.itextpdf.kernel.pdf.PdfAConformanceLevel;
+import com.itextpdf.kernel.pdf.PdfArray;
 import com.itextpdf.kernel.pdf.PdfDictionary;
 import com.itextpdf.kernel.pdf.PdfName;
+import com.itextpdf.kernel.pdf.PdfNumber;
 import com.itextpdf.kernel.pdf.PdfOutputIntent;
 import com.itextpdf.kernel.pdf.PdfPage;
 import com.itextpdf.kernel.pdf.PdfWriter;
+import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
+import com.itextpdf.kernel.pdf.colorspace.PdfColorSpace;
+import com.itextpdf.kernel.pdf.colorspace.PdfDeviceCs;
+import com.itextpdf.kernel.pdf.colorspace.PdfSpecialCs;
+import com.itextpdf.kernel.pdf.function.PdfFunction;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.type.IntegrationTest;
 import com.itextpdf.kernel.xmp.XMPException;
 
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.InputStream;
+import java.util.Collections;
 
 import org.junit.Rule;
 import org.junit.Test;
@@ -82,4 +93,5 @@ public void catalogCheck01() throws FileNotFoundException, XMPException {
 
         doc.close();
     }
+
 }