3 files changed, 45 insertions, 2 deletions
diff --git a/java/src/Ice/InputStreamI.java b/java/src/Ice/InputStreamI.java
index 9ee2c868b4a..cbed1636c37 100644
--- a/java/src/Ice/InputStreamI.java
+++ b/java/src/Ice/InputStreamI.java
@@ -225,7 +225,7 @@ public class InputStreamI implements InputStream
     public void
     endEncapsulation()
     {
-        _is.endReadEncaps();
+        _is.endReadEncapsChecked();
     }
 
     public void
diff --git a/java/src/Ice/OutputStreamI.java b/java/src/Ice/OutputStreamI.java
index 934f8047e85..7cd54936769 100644
--- a/java/src/Ice/OutputStreamI.java
+++ b/java/src/Ice/OutputStreamI.java
@@ -136,6 +136,11 @@ public class OutputStreamI implements OutputStream
     public void
     writeSize(int sz)
     {
+        if(sz < 0)
+        {
+            throw new NegativeSizeException();
+        }
+
         _os.writeSize(sz);
     }
 
@@ -184,7 +189,7 @@ public class OutputStreamI implements OutputStream
     public void
     endEncapsulation()
     {
-        _os.endWriteEncaps();
+        _os.endWriteEncapsChecked();
     }
 
     public void
diff --git a/java/src/IceInternal/BasicStream.java b/java/src/IceInternal/BasicStream.java
index 659995acc2a..2541478d1d6 100644
--- a/java/src/IceInternal/BasicStream.java
+++ b/java/src/IceInternal/BasicStream.java
@@ -367,6 +367,17 @@ public class BasicStream
     }
 
     public void
+    endWriteEncapsChecked() // Used by public stream API.
+    {
+        if(_writeEncapsStack == null)
+        {
+            throw new Ice.EncapsulationException("not in an encapsulation");
+        }
+
+        endWriteEncaps();
+    }
+
+    public void
     startReadEncaps()
     {
         {
@@ -478,6 +489,17 @@ public class BasicStream
         }
     }
 
+    public void
+    endReadEncapsChecked() // Used by public stream API.
+    {
+        if(_readEncapsStack == null)
+        {
+            throw new Ice.EncapsulationException("not in an encapsulation");
+        }
+
+        endReadEncaps();
+    }
+
     public int
     getReadEncapsSize()
     {
@@ -592,6 +614,14 @@ public class BasicStream
     public void
     writeTypeId(String id)
     {
+        if(_writeEncapsStack == null || _writeEncapsStack.typeIdMap == null)
+        {
+            //
+            // writeObject() must be called first.
+            //
+            throw new Ice.MarshalException("type ids require an encapsulation");
+        }
+
         Integer index = _writeEncapsStack.typeIdMap.get(id);
         if(index != null)
         {
@@ -610,6 +640,14 @@ public class BasicStream
     public String
     readTypeId()
     {
+        if(_readEncapsStack == null || _readEncapsStack.typeIdMap == null)
+        {
+            //
+            // readObject() must be called first.
+            //
+            throw new Ice.MarshalException("type ids require an encapsulation");
+        }
+
         String id;
         Integer index;
         final boolean isIndex = readBool();