Fix font selection in case diacritic font doesn't contain previous symbol

DEVSIX-8285

Autoported commit.
Original commit hash: [523702a35]

Author: introfog

itext.tests/itext.layout.tests/itext/layout/font/selectorstrategy/BestMatchFontSelectorStrategyTest.cs

@@ -56,7 +56,7 @@ public virtual void OneDiacriticTest() {
 
         [NUnit.Framework.Test]
         public virtual void OneDiacriticWithUnsupportedFontTest() {
-            IFontSelectorStrategy strategy = FontSelectorTestsUtil.CreateStrategyWithTNR(new FirstMatchFontSelectorStrategy.FirstMathFontSelectorStrategyFactory
+            IFontSelectorStrategy strategy = FontSelectorTestsUtil.CreateStrategyWithTNR(new BestMatchFontSelectorStrategy.BestMatchFontSelectorStrategyFactory
                 ());
             IList<Tuple2<GlyphLine, PdfFont>> result = strategy.GetGlyphLines("L with accent: \u004f\u0302 abc");
             NUnit.Framework.Assert.AreEqual(3, result.Count);
@@ -67,9 +67,25 @@ public virtual void OneDiacriticWithUnsupportedFontTest() {
             NUnit.Framework.Assert.AreEqual(result[0].GetSecond(), result[1].GetSecond());
         }
 
+        [NUnit.Framework.Test]
+        public virtual void DiacriticFontDoesnotContainPreviousSymbolTest() {
+            IFontSelectorStrategy strategy = FontSelectorTestsUtil.CreateStrategyWithNotoSans(new BestMatchFontSelectorStrategy.BestMatchFontSelectorStrategyFactory
+                ());
+            IList<Tuple2<GlyphLine, PdfFont>> result = strategy.GetGlyphLines("Ми\u0301ръ (mírə)");
+            NUnit.Framework.Assert.AreEqual(6, result.Count);
+            NUnit.Framework.Assert.AreEqual("Ми", result[0].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual("\u0301", result[1].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual("ръ", result[2].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual(" (mír", result[3].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual("ə", result[4].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual(")", result[5].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual(result[0].GetSecond(), result[2].GetSecond());
+            NUnit.Framework.Assert.AreEqual(result[2].GetSecond(), result[3].GetSecond());
+        }
+
         [NUnit.Framework.Test]
         public virtual void OneDiacriticWithOneSupportedFontTest() {
-            IFontSelectorStrategy strategy = FontSelectorTestsUtil.CreateStrategyWithFreeSans(new FirstMatchFontSelectorStrategy.FirstMathFontSelectorStrategyFactory
+            IFontSelectorStrategy strategy = FontSelectorTestsUtil.CreateStrategyWithFreeSans(new BestMatchFontSelectorStrategy.BestMatchFontSelectorStrategyFactory
                 ());
             IList<Tuple2<GlyphLine, PdfFont>> result = strategy.GetGlyphLines("L with accent: \u004f\u0302 abc");
             NUnit.Framework.Assert.AreEqual(1, result.Count);

itext.tests/itext.layout.tests/itext/layout/font/selectorstrategy/FirstMatchFontSelectorStrategyTest.cs

@@ -50,6 +50,22 @@ public virtual void OneDiacriticTest() {
             NUnit.Framework.Assert.AreNotEqual(result[0].GetSecond(), result[1].GetSecond());
         }
 
+        [NUnit.Framework.Test]
+        public virtual void DiacriticFontDoesnotContainPreviousSymbolTest() {
+            IFontSelectorStrategy strategy = FontSelectorTestsUtil.CreateStrategyWithNotoSans(new FirstMatchFontSelectorStrategy.FirstMathFontSelectorStrategyFactory
+                ());
+            IList<Tuple2<GlyphLine, PdfFont>> result = strategy.GetGlyphLines("Ми\u0301ръ (mírə)");
+            NUnit.Framework.Assert.AreEqual(6, result.Count);
+            NUnit.Framework.Assert.AreEqual("Ми", result[0].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual("\u0301", result[1].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual("ръ (", result[2].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual("mír", result[3].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual("ə", result[4].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual(")", result[5].GetFirst().ToString());
+            NUnit.Framework.Assert.AreEqual(result[0].GetSecond(), result[2].GetSecond());
+            NUnit.Framework.Assert.AreEqual(result[2].GetSecond(), result[3].GetSecond());
+        }
+
         [NUnit.Framework.Test]
         public virtual void OneDiacriticWithUnsupportedFontTest() {
             IFontSelectorStrategy strategy = FontSelectorTestsUtil.CreateStrategyWithTNR(new FirstMatchFontSelectorStrategy.FirstMathFontSelectorStrategyFactory

itext.tests/itext.layout.tests/itext/layout/font/selectorstrategy/FontSelectorTestsUtil.cs

@@ -41,6 +41,18 @@ public static IFontSelectorStrategy CreateStrategyWithFreeSansAndTNR(IFontSelect
             return fontProvider.CreateFontSelectorStrategy(fontFamilies, new FontCharacteristics(), null);
         }
 
+        public static IFontSelectorStrategy CreateStrategyWithNotoSans(IFontSelectorStrategyFactory factory) {
+            FontSet fs = new FontSet();
+            fs.AddFont(FONTS_FOLDER + "NotoKufiArabic-Regular.ttf");
+            fs.AddFont(FONTS_FOLDER + "NotoSansCJKjp-Regular.otf");
+            fs.AddFont(FONTS_FOLDER + "NotoSansCherokee-Regular.ttf");
+            FontProvider fontProvider = new FontProvider(fs, StandardFontFamilies.TIMES);
+            fontProvider.SetFontSelectorStrategyFactory(factory);
+            IList<String> fontFamilies = new List<String>();
+            fontFamilies.Add("random");
+            return fontProvider.CreateFontSelectorStrategy(fontFamilies, new FontCharacteristics(), null);
+        }
+
         public static IFontSelectorStrategy CreateStrategyWithTNR(IFontSelectorStrategyFactory factory) {
             FontSet fs = new FontSet();
             fs.AddFont(StandardFonts.TIMES_ROMAN);

itext.tests/itext.layout.tests/resources/itext/layout/fonts/NOTICE.txt

@@ -11,6 +11,9 @@ Please notice that the following fonts are used with the mentioned below license
 * NotoSansThai-Regular - SIL Open Font License v1.1
 * Puritan2 - SIL Open Font License v1.1
 * NotoSansOldItalic-Regular.ttf - SIL Open Font License v1.1. Based on commit 20bc5918912503bc1537a407a694738c33c048aa (07.31.2020) from "https://github.com/googlefonts/noto-fonts"
+* NotoSansCJKjp-Regular.otf - SIL Open Font License v1.1
+* NotoSansCherokee-Regular.ttf - SIL Open Font License v1.1
+* NotoKufiArabic-Regular.ttf - SIL Open Font License v1.1
 
 
 

itext.tests/itext.layout.tests/resources/itext/layout/fonts/NotoKufiArabic-Regular.ttf

@@ -117,9 +117,13 @@ public virtual IList<Tuple2<GlyphLine, PdfFont>> GetGlyphLines(String text) {
                         if (i > indexDiacritic) {
                             if (iText.IO.Util.TextUtil.IsDiacritic(codePoint)) {
                                 PdfFont diacriticFont = MatchFont(codePoint, fontSelector, fontProvider, additionalFonts);
+                                // Diacritic font must contain previous symbol, if not, don't
+                                // enable special logic for diacritic and process it as usual symbol
+                                bool isPreviousMatchFont = i == 0 || diacriticFont == null || diacriticFont.ContainsGlyph(ExtractCodePoint
+                                    (text, i - 1));
                                 // If diacritic font equals to the current font or null, don't
                                 // enable special logic for diacritic and process it as usual symbol
-                                if (diacriticFont != null && diacriticFont != currentFont) {
+                                if (diacriticFont != null && diacriticFont != currentFont && isPreviousMatchFont) {
                                     // If it's the first diacritic in a row, we want to break to try to find a better font for
                                     // the previous letter during the next iteration
                                     if (indexDiacritic != i - 1) {

itext.tests/itext.layout.tests/resources/itext/layout/fonts/NotoSansCJKjp-Regular.otf

@@ -1 +1 @@
-c02f3a1c49366516edd50b61e0cc90f41d109455
+523702a3508c09b439be44375f1a7519f731b37e