Make FontData key in map immutable

Creating clone of FontData to be used as a key in map of
ScalingSWTFontRegistry and DefaultSWTFontRegistry to make it immutable and inaccessible from outside of the class

Author: ShahzaibIbrahim

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/internal/DefaultSWTFontRegistry.java

@@ -72,7 +72,8 @@ public Font getFont(FontData fontData, int zoom) {
 	}
 
 	private Font registerFont(FontData fontData, Font font) {
-		fontsMap.put(fontData, font);
+		FontData clonedFontData = new FontData(fontData.toString());
+		fontsMap.put(clonedFontData, font);
 		return font;
 	}
 

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/internal/ScalingSWTFontRegistry.java

@@ -130,8 +130,9 @@ public Font getFont(FontData fontData, int zoom) {
 		if (customFontsKeyMap.containsKey(fontData)) {
 			container = customFontsKeyMap.get(fontData);
 		} else {
-			container = new ScaledCustomFontContainer(fontData);
-			customFontsKeyMap.put(fontData, container);
+			FontData clonedFontData = new FontData(fontData.toString());
+			container = new ScaledCustomFontContainer(clonedFontData);
+			customFontsKeyMap.put(clonedFontData, container);
 		}
 		return container.getScaledFont(zoom);
 	}