If anchor delta is not zero, follow special xPlacement logic even if it's 0

DEVSIX-4472
DEVSIX-4473

Author: ars18wrw

io/src/main/java/com/itextpdf/io/font/otf/Glyph.java

@@ -270,11 +270,12 @@ public void setAnchorDelta(short anchorDelta) {
     }
 
     public boolean hasOffsets() {
-        return xPlacement != 0 || yPlacement != 0 || xAdvance != 0 || yAdvance != 0;
+        return hasAdvance() || hasPlacement();
     }
 
+    // In case some of placement values are not zero we always expect anchorDelta to be non-zero
     public boolean hasPlacement() {
-        return xPlacement != 0 || yPlacement != 0;
+        return anchorDelta != 0;
     }
 
     public boolean hasAdvance() {

io/src/test/java/com/itextpdf/io/font/otf/GlyphTest.java

@@ -0,0 +1,67 @@
+/*
+    This file is part of the iText (R) project.
+    Copyright (c) 1998-2020 iText Group NV
+    Authors: iText Software.
+
+    This program is offered under a commercial and under the AGPL license.
+    For commercial licensing, contact us at https://itextpdf.com/sales.  For AGPL licensing, see below.
+
+    AGPL licensing:
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.itextpdf.io.font.otf;
+
+import com.itextpdf.test.ExtendedITextTest;
+import com.itextpdf.test.annotations.type.UnitTest;
+
+import java.io.IOException;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category(UnitTest.class)
+public class GlyphTest extends ExtendedITextTest {
+
+    @Test
+    public void hasPlacementIfAnchorDeltaNonZeroTest() {
+        Glyph glyph = createDummyGlyph();
+
+        Assert.assertEquals(0, glyph.getXPlacement());
+        Assert.assertEquals(0, glyph.getYPlacement());
+        Assert.assertEquals(0, glyph.getAnchorDelta());
+        Assert.assertFalse(glyph.hasPlacement());
+
+        glyph.setAnchorDelta((short) 10);
+
+        Assert.assertTrue(glyph.hasPlacement());
+    }
+
+    @Test
+    public void hasOffsetsIfAnchorDeltaNonZeroTest() {
+        Glyph glyph = createDummyGlyph();
+
+        Assert.assertEquals(0, glyph.getXPlacement());
+        Assert.assertEquals(0, glyph.getYPlacement());
+        Assert.assertEquals(0, glyph.getAnchorDelta());
+        Assert.assertFalse(glyph.hasOffsets());
+
+        glyph.setAnchorDelta((short) 10);
+
+        Assert.assertTrue(glyph.hasOffsets());
+    }
+
+    private static Glyph createDummyGlyph() {
+        return new Glyph(0, 0, 0);
+    }
+}

kernel/src/main/java/com/itextpdf/kernel/pdf/canvas/PdfCanvas.java

@@ -765,7 +765,8 @@ public PdfCanvas showText(GlyphLine text, Iterator<GlyphLine.GlyphLinePart> iter
                             float xPlacementAddition = 0;
                             int currentGlyphIndex = i;
                             Glyph currentGlyph = text.get(i);
-                            while (currentGlyph != null && currentGlyph.getXPlacement() != 0) {
+                            // if xPlacement is not zero, anchorDelta is expected to be non-zero as well
+                            while (currentGlyph != null && (currentGlyph.getAnchorDelta() != 0)) {
                                 xPlacementAddition += currentGlyph.getXPlacement();
                                 if (currentGlyph.getAnchorDelta() == 0) {
                                     break;