From cccd14559f980b4a293a6413bbab7749c062348b Mon Sep 17 00:00:00 2001
From: Tyler Gregg <greggt@amazon.com>
Date: Thu, 11 Apr 2024 17:12:06 -0700
Subject: [PATCH] Ensures that the cursor's value marker is fully reset between
 values.

---
 .../com/amazon/ion/impl/IonCursorBinary.java  |  1 +
 ...onReaderContinuableTopLevelBinaryTest.java | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/src/main/java/com/amazon/ion/impl/IonCursorBinary.java b/src/main/java/com/amazon/ion/impl/IonCursorBinary.java
index 7e06b6db4e..c426b813ec 100644
--- a/src/main/java/com/amazon/ion/impl/IonCursorBinary.java
+++ b/src/main/java/com/amazon/ion/impl/IonCursorBinary.java
@@ -1094,6 +1094,7 @@ private boolean checkContainerEnd() {
      * Resets state specific to the current value.
      */
     private void reset() {
+        valueMarker.typeId = null;
         valueMarker.startIndex = -1;
         valueMarker.endIndex = -1;
         fieldSid = -1;
diff --git a/src/test/java/com/amazon/ion/impl/IonReaderContinuableTopLevelBinaryTest.java b/src/test/java/com/amazon/ion/impl/IonReaderContinuableTopLevelBinaryTest.java
index cb4d44ae34..a0720710c7 100644
--- a/src/test/java/com/amazon/ion/impl/IonReaderContinuableTopLevelBinaryTest.java
+++ b/src/test/java/com/amazon/ion/impl/IonReaderContinuableTopLevelBinaryTest.java
@@ -3933,6 +3933,25 @@ public void annotationSequenceLengthThatOverflowsBufferThrowsIonException(boolea
         );
     }
 
+    @ParameterizedTest(name = "constructFromBytes={0}")
+    @ValueSource(booleans = {true, false})
+    public void incompleteAnnotationAfterStructFailsCleanly(boolean constructFromBytes) throws Exception {
+        expectIonException(
+            constructFromBytes,
+            reader -> {
+                try {
+                    assertEquals(IonType.STRUCT, reader.next());
+                } catch (Exception e) {
+                    fail();
+                }
+                // This should fail with IonException due to unexpected EOF.
+                reader.next();
+            },
+            0xDF, // null.struct
+            0xE6, 0x81 // Incomplete annotation wrapper declaring length 6
+        );
+    }
+
     /**
      * Verifies that corrupting each byte in the input data results in IonException, or nothing.
      * @param constructFromBytes whether to provide bytes (true) or an InputStream (false) to the reader.