JBR-2924 Do not try to create native italic font when we're going to make it fake italic

(cherry picked from commit cf05cb1a19)

src/java.desktop/macosx/classes/sun/font/CFont.java

@@ -187,7 +187,10 @@ public final class CFont extends PhysicalFont implements FontSubstitution, FontW
 
     protected synchronized long getNativeFontPtr() {
         if (nativeFontPtr == 0L) {
-            nativeFontPtr = createNativeFont(nativeFontName, style);
+            /* Do not try to create native italic font when isFakeItalic
+             * is true, otherwise we can make it italic twice */
+            nativeFontPtr = createNativeFont(nativeFontName, style &
+                    (isFakeItalic ? ~Font.ITALIC : -1));
         }
         return nativeFontPtr;
     }

test/jdk/java/awt/font/Italic/SFNSItalicTest.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2000-2021 JetBrains s.r.o.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @summary SFNS italic font inclination on macOS
+ * @requires os.family == "mac"
+ */
+
+import javax.imageio.ImageIO;
+import java.awt.*;
+import java.awt.geom.Point2D;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.util.List;
+import java.util.ArrayList;
+
+public class SFNSItalicTest {
+    /**
+     * 0.2 is a default inclination for italic fonts, see {@link sun.font.CFont#createStrike}
+     */
+    private static final double TARGET_INCLINATION = 0.2;
+    private static final double TARGET_INCLINATION_ERROR = 0.01;
+    private static final char SYMBOL = 'I';
+    private static final Font FONT = new Font(".SFNS-Regular", Font.ITALIC, 16);
+    private static final int IMAGE_WIDTH = 20;
+    private static final int IMAGE_HEIGHT = 20;
+    private static final int GLYPH_X = 6;
+    private static final int GLYPH_Y = 16;
+
+    public static void main(String[] args) throws Exception {
+        BufferedImage image = createImage();
+        double inclination = getInclination(image);
+        if (inclination < TARGET_INCLINATION - TARGET_INCLINATION_ERROR ||
+            inclination > TARGET_INCLINATION + TARGET_INCLINATION_ERROR) {
+            File file = new File( "SFNS-italic.png");
+            ImageIO.write(image, "PNG", file);
+            throw new RuntimeException("Incorrect inclination. Expected: " + TARGET_INCLINATION + "+-" +
+                    TARGET_INCLINATION_ERROR + ", Actual: " + inclination + ", see " + file);
+        }
+    }
+
+    private static BufferedImage createImage() {
+        BufferedImage image = new BufferedImage(IMAGE_WIDTH, IMAGE_HEIGHT, BufferedImage.TYPE_INT_RGB);
+        Graphics2D g = image.createGraphics();
+        g.setColor(Color.black);
+        g.fillRect(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT);
+        g.setColor(Color.white);
+        g.setFont(FONT);
+        g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+        g.drawString(String.valueOf(SYMBOL), GLYPH_X, GLYPH_Y);
+        g.dispose();
+        return image;
+    }
+
+    private static double getInclination(BufferedImage image) {
+        List<Point2D> points = new ArrayList<>(IMAGE_HEIGHT);
+        double mx = 0, my = 0;
+        for (int y = 0; y < image.getHeight(); y++) {
+            double totalWeight = 0;
+            double weightedX = 0;
+            for (int x = 0; x < image.getWidth(); x++) {
+                double weight = (image.getRGB(x, y) & 0xFF) / 255.0;
+                weightedX += x * weight;
+                totalWeight += weight;
+            }
+            double x = weightedX / totalWeight;
+            if (Double.isFinite(x)) {
+                mx += x;
+                my += y;
+                points.add(new Point2D.Double(x, y));
+            }
+        }
+        mx /= points.size();
+        my /= points.size();
+        double xySum = 0;
+        double y2Sum = 0;
+        for (Point2D p : points) {
+            xySum += (p.getX() - mx) * (p.getY() - my);
+            y2Sum += Math.pow(p.getY() - my, 2);
+        }
+        return -xySum / y2Sum;
+    }
+}