Add set to IntList

Some applications may wish to modify an int list.

Bug: 291083
Eclipse-CQ: 3559
Change-Id: Iea871443ec661230aec92397229f1eda6c74216f
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit.test/tst/org/eclipse/jgit/util/IntListTest.java

 		}
 	}
 
+	public void testSet() {
+		final IntList i = new IntList();
+		i.add(1);
+		assertEquals(1, i.size());
+		assertEquals(1, i.get(0));
+
+		i.set(0, 5);
+		assertEquals(5, i.get(0));
+
+		try {
+			i.set(5, 5);
+			fail("accepted set of 5 beyond end of list");
+		} catch (ArrayIndexOutOfBoundsException e){
+			assertTrue(true);
+		}
+
+		i.set(1, 2);
+		assertEquals(2, i.size());
+		assertEquals(2, i.get(1));
+	}
+
 	public void testToString() {
 		final IntList i = new IntList();
 		i.add(1);

org.eclipse.jgit/src/org/eclipse/jgit/util/IntList.java

 /*
  * Copyright (C) 2008, Google Inc.
+ * Copyright (C) 2009, Johannes Schindelin <johannes.schindelin@gmx.de>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
 		entries[count++] = n;
 	}
 
+	/**
+	 * Assign an entry in the list.
+	 *
+	 * @param index
+	 *            index to set, must be in the range [0, {@link #size()}).
+	 * @param n
+	 *            value to store at the position.
+	 */
+	public void set(final int index, final int n) {
+		if (count < index)
+			throw new ArrayIndexOutOfBoundsException(index);
+		else if (count == index)
+			add(n);
+		else
+			entries[index] = n;
+	}
+
 	/**
 	 * Pad the list with entries.
 	 *