diff --git a/delta2/delta2.c b/delta2/delta2.c
index f48d41e..c7274ad 100644
--- a/delta2/delta2.c
+++ b/delta2/delta2.c
@@ -127,6 +127,8 @@ delta2_encode(uchar_t *src, uint64_t srclen, uchar_t *dst, uint64_t *dstlen, int
 		*((uint64_t *)dst) = LE64(srclen);
 		dst += MAIN_HDR;
 		rv = delta2_encode_real(src, srclen, dst, dstlen, rle_thresh, 1, &hdr_ovr);
+		if (rv == -1)
+			return (rv);
 		*dstlen += MAIN_HDR;
 		DEBUG_STAT_EN(fprintf(stderr, "DELTA2: srclen: %" PRIu64 ", dstlen: %" PRIu64 "\n", srclen, *dstlen));
 		DEBUG_STAT_EN(fprintf(stderr, "DELTA2: header overhead: %d\n", hdr_ovr));
@@ -288,7 +290,7 @@ delta2_encode_real(uchar_t *src, uint64_t srclen, uchar_t *dst, uint64_t *dstlen
 
 	/*
 	 * No need to check for destination buffer overflow since
-	 * dstlen == srclen always.
+	 * dstlen >= srclen always.
 	 */
 	if ( gtot1 > (srclen - (DELTA_HDR + LIT_HDR + MAIN_HDR)) ) {
 		if (srclen == DELTA2_CHUNK) {
diff --git a/main.c b/main.c
index 79535c0..eb7b02f 100644
--- a/main.c
+++ b/main.c
@@ -264,7 +264,6 @@ preproc_compress(compress_func_ptr cmp_func, void *src, uint64_t srclen, void *d
 		if (type > 0)
 			result = 0;
 	}
-
 	return (result);
 }
 
@@ -1489,8 +1488,12 @@ start_compress(const char *filename, uint64_t chunksize, int level)
 		else
 			flags |= FLAG_DEDUP_FIXED;
 		/* Additional scratch space for dedup arrays. */
-		compressed_chunksize += (dedupe_buf_extra(chunksize, 0, algo,
-			enable_delta_encode) - (compressed_chunksize - chunksize));
+		if (chunksize + dedupe_buf_extra(chunksize, 0, algo, enable_delta_encode)
+		    > compressed_chunksize) {
+			compressed_chunksize += (chunksize +
+			    dedupe_buf_extra(chunksize, 0, algo, enable_delta_encode)) -
+			    compressed_chunksize;
+		}
 	}
 
 	if (encrypt_type) {
diff --git a/test/run_test.sh b/test/run_test.sh
index 44c36d1..7c349c5 100644
--- a/test/run_test.sh
+++ b/test/run_test.sh
@@ -52,12 +52,9 @@ then
 		[ $? -ne 0 ] && continue
 
 		cd datafiles
-		(. ../${tf})
-		if [ $? -ne 0 ]
-		then
-			echo "FATAL: Test ${tf} failed"
-			failures=$((failures + 1))
-		fi
+		(. ../${tf}) 2>&1 | tee ${tf}.log
+		fails=`egrep "^FATAL:" ${tf}.log | wc -l`
+		failures=$((failures + fails))
 		cd $PDIR
 	done
 else