Fixes a bug that caused the binary reader not to fail cleanly when parsing incomplete containers in certain cases.

src/main/java/com/amazon/ion/impl/IonCursorBinary.java

@@ -1574,6 +1574,9 @@ private boolean uncheckedNextToken() {
             if (uncheckedNextContainedToken()) {
                 return false;
             }
+            if (peekIndex >= limit) {
+                throw new IonException("Malformed data: declared length exceeds the number of bytes remaining in the container.");
+            }
             b = buffer[(int)(peekIndex++)] & SINGLE_BYTE_MASK;
         }
         if (uncheckedReadHeader(b, false, valueMarker)) {

src/test/java/com/amazon/ion/impl/IonReaderContinuableCoreBinaryTest.java

@@ -3,6 +3,7 @@
 
 package com.amazon.ion.impl;
 
+import com.amazon.ion.IonCursor;
 import com.amazon.ion.IonException;
 import com.amazon.ion.IonType;
 import org.junit.jupiter.api.Test;
@@ -496,4 +497,74 @@ public void expectLobWithOverflowingEndIndexToFailCleanly(boolean constructFromB
         assertThrows(IonException.class, reader::nextValue);
         reader.close();
     }
+
+    @Test
+    public void expectIncompleteContainerToFailCleanlyAfterFieldSid() {
+        IonReaderContinuableCoreBinary reader = initializeReader(
+            true,
+            0xE0, 0x01, 0x00, 0xEA, // IVM
+            0xDC, // Struct, length 12
+            0x9A  // Field SID 26
+            // The struct ends unexpectedly
+        );
+        assertEquals(IonCursor.Event.START_CONTAINER, reader.nextValue());
+        assertEquals(IonType.STRUCT, reader.getType());
+        reader.stepIntoContainer();
+        // This is an unexpected EOF, so the reader should fail cleanly.
+        assertThrows(IonException.class, reader::nextValue);
+        reader.close();
+    }
+
+    @Test
+    public void expectIncompleteContainerToFailCleanlyAfterTwoByteFieldSid() {
+        IonReaderContinuableCoreBinary reader = initializeReader(
+            true,
+            0xE0, 0x01, 0x00, 0xEA, // IVM
+            0xDC, // Struct, length 12
+            0x00, // First byte of overpadded 2-byte field SID
+            0x9A  // Field SID 26
+            // The struct ends unexpectedly
+        );
+        assertEquals(IonCursor.Event.START_CONTAINER, reader.nextValue());
+        assertEquals(IonType.STRUCT, reader.getType());
+        reader.stepIntoContainer();
+        // This is an unexpected EOF, so the reader should fail cleanly.
+        assertThrows(IonException.class, reader::nextValue);
+        reader.close();
+    }
+
+    @Test
+    public void expectIncompleteContainerToFailCleanlyAfterAnnotationHeader() {
+        IonReaderContinuableCoreBinary reader = initializeReader(
+            true,
+            0xE0, 0x01, 0x00, 0xEA, // IVM
+            0xDC, // Struct, length 12
+            0x9A, // Field SID 26
+            0xE4, // Annotation wrapper length 4
+            0x00, 0x81, // VarUInt length 1 (overpadded by 1 byte)
+            0x00, 0x84  // VarUInt SID 4 (overpadded by 1 byte)
+            // The value ends unexpectedly
+        );
+        assertEquals(IonCursor.Event.START_CONTAINER, reader.nextValue());
+        assertEquals(IonType.STRUCT, reader.getType());
+        reader.stepIntoContainer();
+        // This is an unexpected EOF, so the reader should fail cleanly.
+        assertThrows(IonException.class, reader::nextValue);
+        reader.close();
+    }
+
+    @Test
+    public void expectIncompleteAnnotationHeaderToFailCleanly() {
+        IonReaderContinuableCoreBinary reader = initializeReader(
+            true,
+            0xE0, 0x01, 0x00, 0xEA, // IVM
+            0xE4, // Annotation wrapper length 5
+            0x81, // VarUInt length 1
+            0x84  // VarUInt SID 4
+            // The value ends unexpectedly
+        );
+        // This is an unexpected EOF, so the reader should fail cleanly.
+        assertThrows(IonException.class, reader::nextValue);
+        reader.close();
+    }
 }