Fix behavior for svg containing elements with zero or negative stroke-width

DEVSIX-6270

Author: AnhelinaM

svg/src/main/java/com/itextpdf/svg/renderers/impl/AbstractSvgNodeRenderer.java

@@ -695,13 +695,16 @@ private StrokeProperties calculateStrokeProperties(SvgDrawContext context) {
         if (!SvgConstants.Values.NONE.equalsIgnoreCase(strokeRawValue)) {
             String strokeWidthRawValue = getAttribute(SvgConstants.Attributes.STROKE_WIDTH);
 
-            // 1 px = 0,75 pt
-            float strokeWidth = 0.75f;
-
+            float strokeWidth = -1;
             if (strokeWidthRawValue != null) {
                 strokeWidth = parseHorizontalLength(strokeWidthRawValue, context);
             }
 
+            if (strokeWidth < 0) {
+                // Default: 1 px = 0,75 pt
+                strokeWidth = 0.75f;
+            }
+
             float generalOpacity = getOpacity();
             float strokeOpacity = getOpacityByAttributeName(SvgConstants.Attributes.STROKE_OPACITY, generalOpacity);
 
@@ -719,8 +722,10 @@ private StrokeProperties calculateStrokeProperties(SvgDrawContext context) {
                     SvgStrokeParameterConverter.convertStrokeDashParameters(strokeDashArrayRawValue,
                             strokeDashOffsetRawValue, getCurrentFontSize(context), context);
 
-            doStroke = true;
-            return new StrokeProperties(strokeColor, strokeWidth, strokeOpacity, lineDashParameters);
+            if (strokeWidth > 0) {
+                doStroke = true;
+                return new StrokeProperties(strokeColor, strokeWidth, strokeOpacity, lineDashParameters);
+            }
         }
         return null;
     }

svg/src/test/java/com/itextpdf/svg/renderers/StrokeTest.java

@@ -25,6 +25,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.test.ITextTest;
 
 import java.io.IOException;
+
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.api.Test;
@@ -103,14 +104,24 @@ public void strokeAttributesTest() throws IOException, InterruptedException {
         convertAndCompare(SOURCE_FOLDER, DESTINATION_FOLDER, "stroke-attributes");
     }
 
+    @Test
+    public void zeroStrokeWidthTest() throws IOException, InterruptedException {
+        convertAndCompareSinglePage(SOURCE_FOLDER, DESTINATION_FOLDER, "zeroStrokeWidth");
+    }
+
+    @Test
+    public void negativeStrokeWidthTest() throws IOException, InterruptedException {
+        convertAndCompareSinglePage(SOURCE_FOLDER, DESTINATION_FOLDER, "negativeStrokeWidth");
+    }
+
     @Test
     public void heightWidthZeroTest() throws IOException, InterruptedException {
-        convertAndCompareSinglePage(SOURCE_FOLDER, DESTINATION_FOLDER,"heightWidthZero");
+        convertAndCompareSinglePage(SOURCE_FOLDER, DESTINATION_FOLDER, "heightWidthZero");
     }
 
     @Test
     public void heightWidthNegativeTest() throws IOException, InterruptedException {
-        convertAndCompareSinglePage(SOURCE_FOLDER, DESTINATION_FOLDER,"heightWidthNegative");
+        convertAndCompareSinglePage(SOURCE_FOLDER, DESTINATION_FOLDER, "heightWidthNegative");
     }
 
     @Test