8245159: Font.getStringBounds() throws IAE for empty string if the Font has layout attributes

prrace · prrace · commit ca2df0e5431d · 2020-07-19T11:03:50.000-07:00
Reviewed-by: serb
diff --git a/src/java.desktop/share/classes/java/awt/Font.java b/src/java.desktop/share/classes/java/awt/Font.java
@@ -2601,7 +2601,7 @@ public Rectangle2D getStringBounds(char [] chars,
             simple = ! FontUtilities.isComplexText(chars, beginIndex, limit);
         }
 
-        if (simple) {
+        if (simple || ((limit - beginIndex) == 0)) {
             FontDesignMetrics metrics = FontDesignMetrics.getMetrics(this, frc);
             return metrics.getSimpleBounds(chars, beginIndex, limit-beginIndex);
         } else {
diff --git a/test/jdk/java/awt/FontClass/ZeroWidthStringBoundsTest.java b/test/jdk/java/awt/FontClass/ZeroWidthStringBoundsTest.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ * 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
+ * @bug 8245159
+ * @summary Ensure no exception getting bounds of an empty string when the font has
+ * layout attributes.
+ * @run main/othervm ZeroWidthStringBoundsTest
+ */
+
+import java.awt.Font;
+import java.awt.font.FontRenderContext;
+import java.awt.font.TextAttribute;
+import java.text.AttributedCharacterIterator;
+import java.util.HashMap;
+
+public class ZeroWidthStringBoundsTest {
+
+   public static void main(String[] args) {
+       FontRenderContext frc = new FontRenderContext(null, false, false);
+       Font f1 = new Font(Font.MONOSPACED, Font.PLAIN, 12);
+       f1.getStringBounds("", frc);
+       HashMap<AttributedCharacterIterator.Attribute, Object> attrs = new HashMap<>();
+       attrs.put(TextAttribute.KERNING, TextAttribute.KERNING_ON);
+       Font f2 = f1.deriveFont(attrs);
+       f2.getStringBounds("", frc);
+   }
+}

Original file line number	Diff line number	Diff line change
`@@ -2601,7 +2601,7 @@ public Rectangle2D getStringBounds(char [] chars,`
`2601`	`2601`	`simple = ! FontUtilities.isComplexText(chars, beginIndex, limit);`
`2602`	`2602`	`}`
`2603`	`2603`
`2604`		`- if (simple) {`
	`2604`	`+ if (simple \|\| ((limit - beginIndex) == 0)) {`
`2605`	`2605`	`FontDesignMetrics metrics = FontDesignMetrics.getMetrics(this, frc);`
`2606`	`2606`	`return metrics.getSimpleBounds(chars, beginIndex, limit-beginIndex);`
`2607`	`2607`	`} else {`