Index: oak-segment-tar/src/test/java/org/apache/jackrabbit/oak/segment/SegmentBufferWriterTest.java
===================================================================
--- oak-segment-tar/src/test/java/org/apache/jackrabbit/oak/segment/SegmentBufferWriterTest.java	(revision 1839550)
+++ oak-segment-tar/src/test/java/org/apache/jackrabbit/oak/segment/SegmentBufferWriterTest.java	(working copy)
@@ -24,7 +24,9 @@
 import static org.junit.Assert.assertNotEquals;
 
 import java.io.File;
+import java.util.Collections;
 import java.util.List;
+import java.util.Random;
 
 import org.apache.jackrabbit.oak.plugins.memory.EmptyNodeState;
 import org.apache.jackrabbit.oak.segment.file.FileStore;
@@ -96,4 +98,38 @@
         assertNotEquals(before, after);
     }
 
+    @Test
+    public void tooBigRecord() throws Exception {
+        try (FileStore store = openFileStore()) {
+
+            // Please don't change anything from the following statement yet.
+            // Read the next comment to understand why.
+
+            SegmentBufferWriter writer = new SegmentBufferWriter(
+                store.getSegmentIdProvider(),
+                store.getReader(),
+                "t",
+                store.getRevisions().getHead().getSegment().getGcGeneration()
+            );
+
+            // The size of the record is chosen with the precise intention to
+            // fool `writer` into having enough space to write the record. In
+            // particular, at the end of `prepare()`, `writer` will have
+            // `this.length = 262144`, which is `MAX_SEGMENT_SIZE`, and
+            // `this.position = 0`. This result is particularly sensitive to the
+            // initial content of the segment, which in turn is influenced by
+            // the segment info. Try to change the writer ID in the constructor
+            // of `SegmentBufferWriter` to a longer string, and you will have
+            // `prepare()` throw ISEs because the writer ID is embedded in the
+            // segment info.
+
+            int size = 262101;
+            writer.prepare(RecordType.BLOCK, size, Collections.emptyList(), store);
+            byte[] data = new byte[size];
+            new Random().nextBytes(data);
+            writer.writeBytes(data, 0, size);
+            writer.flush(store);
+        }
+    }
+
 }