Fix text wrap for border cases when next symbol almost fits on the line

DEVSIX-7146

Author: Vitali Prudnikovich

layout/src/main/java/com/itextpdf/layout/renderer/TextRenderer.java

@@ -378,10 +378,10 @@ public LayoutResult layout(LayoutContext layoutContext) {
                     xAdvance = scaleXAdvance(xAdvance, fontSize.getValue(), hScale) / TEXT_SPACE_COEFF;
                 }
 
-                float potentialWidth =
+                final float potentialWidth =
                         nonBreakablePartFullWidth + glyphWidth + xAdvance + italicSkewAddition + boldSimulationAddition;
-                if (!noSoftWrap && (potentialWidth > layoutBox.getWidth() - currentLineWidth + EPS)
-                        && firstCharacterWhichExceedsAllowedWidth == -1
+                final boolean symbolNotFitOnLine = potentialWidth > layoutBox.getWidth() - currentLineWidth + EPS;
+                if ((!noSoftWrap && symbolNotFitOnLine && firstCharacterWhichExceedsAllowedWidth == -1)
                         || ind == specialScriptFirstNotFittingIndex) {
                     firstCharacterWhichExceedsAllowedWidth = ind;
                     boolean spaceOrWhitespace = TextUtil.isSpaceOrWhitespace(text.get(ind));
@@ -423,8 +423,7 @@ public LayoutResult layout(LayoutContext layoutContext) {
 
                 previousCharPos = ind;
 
-                if (!noSoftWrap
-                        && nonBreakablePartFullWidth + italicSkewAddition + boldSimulationAddition > layoutBox.getWidth()
+                if (!noSoftWrap && symbolNotFitOnLine
                         && (0 == nonBreakingHyphenRelatedChunkWidth || ind + 1 == text.end || !glyphBelongsToNonBreakingHyphenRelatedChunk(text, ind + 1))) {
                     if (isOverflowFit(overflowX)) {
                         // we have extracted all the information we wanted and we do not want to continue.

layout/src/test/java/com/itextpdf/layout/TextWritingTest.java

@@ -46,6 +46,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.colors.ColorConstants;
 import com.itextpdf.kernel.font.PdfFont;
 import com.itextpdf.kernel.font.PdfFontFactory;
+import com.itextpdf.kernel.geom.PageSize;
 import com.itextpdf.kernel.pdf.PdfDocument;
 import com.itextpdf.kernel.pdf.PdfWriter;
 import com.itextpdf.kernel.pdf.canvas.PdfCanvasConstants;
@@ -59,6 +60,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.layout.properties.Property;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.type.IntegrationTest;
+
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -403,4 +405,41 @@ public void leadingAndFloatInTextTest() throws IOException, InterruptedException
 
         Assert.assertNull(new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder));
     }
+
+    @Test
+    public void textWrappingEpsilonTest() throws IOException, InterruptedException {
+        String outFileName = destinationFolder + "textWrappingEpsilon.pdf";
+        String cmpFileName = sourceFolder + "cmp_textWrappingEpsilon.pdf";
+
+        PdfWriter writer = new PdfWriter(outFileName);
+        PdfDocument pdfDoc = new PdfDocument(writer);
+        Document document = new Document(pdfDoc);
+
+        // Play with margins to make AbstractRenderer.EPS important for wrapping behavior
+        document.setLeftMargin(250.0F);
+        document.setRightMargin(238.727F);
+        pdfDoc.setDefaultPageSize(PageSize.LETTER);
+        PdfFont font = PdfFontFactory.createFont(sourceFolder + "../fonts/Open_Sans/OpenSans-Regular.ttf");
+
+        String text1 = "First line of some text ";
+        String text2 = "Second line of some text";
+
+        Text text = new Text(text1);
+        text.setFont(font);
+        text.setFontSize(9);
+        Paragraph paragraph = new Paragraph();
+        paragraph.add(text);
+
+        text = new Text(text2);
+        text.setFont(font);
+        text.setFontSize(9);
+        paragraph.add(text);
+
+        paragraph.setBackgroundColor(ColorConstants.LIGHT_GRAY);
+        document.add(paragraph);
+        document.close();
+        writer.close();
+
+        Assert.assertNull(new CompareTool().compareByContent(outFileName, cmpFileName, destinationFolder));
+    }
 }