[JGIT PATCH 02/23] Add MutableObjectId.clear() to set the id to zeroId

This makes it easier to set any MutableObjectId to the same value
as the zeroId.  Its logical to ask for a ".clear()" invocation when
you are writing application code, and its more efficient for the
JIT if we do 5 zero writes then to perform a copy from the zeroId
singleton.

Signed-off-by: Shawn O. Pearce <redacted>
---
 .../src/org/spearce/jgit/lib/MutableObjectId.java  |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/MutableObjectId.java b/org.spearce.jgit/src/org/spearce/jgit/lib/MutableObjectId.java
index 5b16345..fadebab 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/MutableObjectId.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/MutableObjectId.java

@@ -66,6 +66,15 @@ MutableObjectId(MutableObjectId src) {
 		this.w5 = src.w5;
 	}
 
+	/** Make this id match {@link ObjectId#zeroId()}. */
+	public void clear() {
+		w1 = 0;
+		w2 = 0;
+		w3 = 0;
+		w4 = 0;
+		w5 = 0;
+	}
+
 	/**
 	 * Convert an ObjectId from raw binary representation.
 	 * 

-- 
1.6.1.rc4.301.g5497a