Fix UnionInputStream.read to be more Java-like

Relax the read() method to not block until exactly "len" bytes have
been read. Instead, return when one or more bytes have been read, up
to "len", so UnionInputStream more closely resembles InputStream's
read() method.

Change-Id: I3f632be8eb85a4a0baf27c9f067c8d817162de2b

1 files changed, 8 insertions, 13 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/io/UnionInputStream.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/io/UnionInputStream.java
index 0df3775f11..20dcd4659e 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/io/UnionInputStream.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/io/UnionInputStream.java
@@ -138,23 +138,18 @@ public class UnionInputStream extends InputStream {
 
 	@Override
 	public int read(byte[] b, int off, int len) throws IOException {
-		int cnt = 0;
-		while (0 < len) {
+		if (len == 0)
+			return 0;
+		for (;;) {
 			final InputStream in = head();
 			final int n = in.read(b, off, len);
-			if (0 < n) {
-				cnt += n;
-				off += n;
-				len -= n;
-			} else if (in == EOF)
-				return 0 < cnt ? cnt : -1;
-			else {
+			if (0 < n)
+				return n;
+			else if (in == EOF)
+				return -1;
+			else
 				pop();
-				if (0 < cnt)
-					break;
-			}
 		}
-		return cnt;
 	}
 
 	@Override