bug fix for writeBinary ensureCapacity, fix issue #537

core/src/main/java/com/alibaba/fastjson2/JSONWriterJSONB.java

@@ -1636,7 +1636,7 @@ public void writeBinary(byte[] bytes) {
             return;
         }
 
-        ensureCapacity(off + 5 + bytes.length);
+        ensureCapacity(off + 6 + bytes.length);
         this.bytes[off++] = BC_BINARY;
         writeInt32(bytes.length);
 

core/src/test/java/com/alibaba/fastjson2/issues/Issue537.java

@@ -0,0 +1,19 @@
+package com.alibaba.fastjson2.issues;
+
+import com.alibaba.fastjson2.JSONWriter;
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.Field;
+
+public class Issue537 {
+    @Test
+    public void test() throws Exception {
+        JSONWriter writer = JSONWriter.ofJSONB();
+        Field field = writer.getClass().getDeclaredField("bytes");
+        field.setAccessible(true);
+        field.set(writer, new byte[1024 * 1024 + 5]);
+
+        byte[] bytes = new byte[1024 * 1024];
+        writer.writeBinary(bytes);
+    }
+}