Improve font characteristics parsing at FontSelector level

Parse font characteristics of specific font-family rather than
falsely reuse the characteristics of the previously parse family

DEVSIX-5587

Autoported commit.
Original commit hash: [a0654a1ed]

Author: dmitry.radchuk

itext.tests/itext.layout.tests/itext/layout/FontSelectorTest.cs

@@ -878,6 +878,31 @@ public virtual void OpenSansOutOfNotBoldFontWeightTest() {
                 ().GetDescriptor().GetFontName());
         }
 
+        [NUnit.Framework.Test]
+        public virtual void FontCharacteristicIsUnmodifiedTest() {
+            FontSet set = GetOpenSansFontSet();
+            IList<String> fontFamilies = new List<String>();
+            fontFamilies.Add("OpenSans italic");
+            fontFamilies.Add("OpenSans bold");
+            FontCharacteristics fc = new FontCharacteristics();
+            FontCharacteristics expectedFc = new FontCharacteristics(fc);
+            // previously font characteristics might have been updated while sorting fonts
+            new FontSelector(set.GetFonts(), fontFamilies, fc);
+            NUnit.Framework.Assert.AreEqual(expectedFc, fc);
+        }
+
+        [NUnit.Framework.Test]
+        public virtual void FontCharacteristicsNullTest() {
+            FontSet set = GetOpenSansFontSet();
+            IList<String> fontFamilies = new List<String>();
+            fontFamilies.Add("test");
+            FontCharacteristics fc = null;
+            FontSelector fontSelector = new FontSelector(set.GetFonts(), fontFamilies, fc);
+            // We expect default font characteristics to be used, e.g. as a result regular font must be the best
+            NUnit.Framework.Assert.AreEqual("OpenSans-Regular", fontSelector.BestMatch().GetDescriptor().GetFontName()
+                );
+        }
+
         private void CheckSelector(ICollection<FontInfo> fontInfoCollection, String fontFamily, String expectedNormal
             , String expectedBold, String expectedItalic, String expectedBoldItalic) {
             IList<String> fontFamilies = new List<String>();

itext.tests/itext.svg.tests/resources/itext/svg/processors/impl/font/FontFaceTest/cmp_droidSerifSingleQuotesTest.pdf

@@ -132,29 +132,30 @@ public virtual int Compare(FontInfo o1, FontInfo o2) {
                 for (int i = 0; i < fontFamilies.Count && res == 0; i++) {
                     FontCharacteristics fc = fontStyles[i];
                     String fontFamily = fontFamilies[i];
-                    if ("monospace".EqualsIgnoreCase(fontFamily)) {
-                        fc.SetMonospaceFlag(true);
-                    }
                     bool isLastFontFamilyToBeProcessed = i == fontFamilies.Count - 1;
                     res = CharacteristicsSimilarity(fontFamily, fc, o2, isLastFontFamilyToBeProcessed) - CharacteristicsSimilarity
                         (fontFamily, fc, o1, isLastFontFamilyToBeProcessed);
                 }
                 return res;
             }
 
-            private static FontCharacteristics ParseFontStyle(String fontFamily, FontCharacteristics fc) {
-                if (fc == null) {
-                    fc = new FontCharacteristics();
+            private static FontCharacteristics ParseFontStyle(String fontFamily, FontCharacteristics defaultFc) {
+                if (defaultFc == null) {
+                    defaultFc = new FontCharacteristics();
                 }
-                if (fc.IsUndefined()) {
+                FontCharacteristics parsedFc = new FontCharacteristics(defaultFc);
+                if (parsedFc.IsUndefined()) {
+                    if ("monospace".EqualsIgnoreCase(fontFamily)) {
+                        parsedFc.SetMonospaceFlag(true);
+                    }
                     if (fontFamily.Contains("bold")) {
-                        fc.SetBoldFlag(true);
+                        parsedFc.SetBoldFlag(true);
                     }
                     if (fontFamily.Contains("italic") || fontFamily.Contains("oblique")) {
-                        fc.SetItalicFlag(true);
+                        parsedFc.SetItalicFlag(true);
                     }
                 }
-                return fc;
+                return parsedFc;
             }
 
             /// <summary>

itext/itext.layout/itext/layout/font/FontSelector.cs

@@ -1 +1 @@
-4ef5318967b79f6fc1cc8b4197f1fe9ee9b8e186
+a0654a1ed99416c1597d6d34739d1538368d2cb4