From be1ca997a75b14ab5893ec5d71a6fddc0b49e8bf Mon Sep 17 00:00:00 2001
From: Andrea Cavalli <andrea@cavallium.it>
Date: Thu, 23 Sep 2021 23:45:41 +0200
Subject: [PATCH] Bugfix

---
 .../cavallium/dbengine/database/LLUtils.java  | 32 +++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/main/java/it/cavallium/dbengine/database/LLUtils.java b/src/main/java/it/cavallium/dbengine/database/LLUtils.java
index 16f38cb..8140892 100644
--- a/src/main/java/it/cavallium/dbengine/database/LLUtils.java
+++ b/src/main/java/it/cavallium/dbengine/database/LLUtils.java
@@ -619,7 +619,17 @@ public class LLUtils {
 	public static Buffer compositeBuffer(BufferAllocator alloc,
 			@NotNull Send<Buffer> buffer1,
 			@NotNull Send<Buffer> buffer2) {
-		return CompositeBuffer.compose(alloc, buffer1, buffer2);
+		var b1 = buffer1.receive();
+		try (var b2 = buffer2.receive()) {
+			if (b1.writerOffset() < b1.capacity() || b2.writerOffset() < b2.capacity()) {
+				b1.ensureWritable(b2.readableBytes(), b2.readableBytes(), true);
+				b2.copyInto(b2.readerOffset(), b1, b1.writerOffset(), b2.readableBytes());
+				b1.writerOffset(b1.writerOffset() + b2.readableBytes());
+				return b1;
+			} else {
+				return CompositeBuffer.compose(alloc, b1.send(), b2.send());
+			}
+		}
 	}
 
 	@NotNull
@@ -627,7 +637,25 @@ public class LLUtils {
 			@NotNull Send<Buffer> buffer1,
 			@NotNull Send<Buffer> buffer2,
 			@NotNull Send<Buffer> buffer3) {
-		return CompositeBuffer.compose(alloc, buffer1, buffer2, buffer3);
+		var b1 = buffer1.receive();
+		try (var b2 = buffer2.receive()) {
+			try (var b3 = buffer3.receive()) {
+				if (b1.writerOffset() < b1.capacity()
+						|| b2.writerOffset() < b2.capacity()
+						|| b3.writerOffset() < b3.capacity()) {
+					b1.ensureWritable(b2.readableBytes(), b2.readableBytes(), true);
+					b2.copyInto(b2.readerOffset(), b1, b1.writerOffset(), b2.readableBytes());
+					b1.writerOffset(b1.writerOffset() + b2.readableBytes());
+
+					b1.ensureWritable(b3.readableBytes(), b3.readableBytes(), true);
+					b3.copyInto(b3.readerOffset(), b1, b1.writerOffset(), b3.readableBytes());
+					b1.writerOffset(b1.writerOffset() + b3.readableBytes());
+					return b1;
+				} else {
+					return CompositeBuffer.compose(alloc, b1.send(), b2.send(), b3.send());
+				}
+			}
+		}
 	}
 
 	public static <T> Mono<T> resolveDelta(Mono<Delta<T>> prev, UpdateReturnMode updateReturnMode) {