Throw OutOfSpaceException instead of IllegalArgumentException.

When a MessageNano containing a String is serialized into a buffer that
is too small to contain it, and the buffer's boundary happens to be
where the string field's length delimiting varint is serialized,
and the string's length and 3*length have the same length when
encoded as a varint, an IllegalArgumentException is thrown rather than
an OutOfSpaceException.

Github issue: https://github.com/google/protobuf/issues/292

Change-Id: If478d68cf15bfd0662252d008e42b2bf1ff1c75e

1 files changed, 10 insertions, 1 deletions

diff --git a/java/src/main/java/com/google/protobuf/nano/CodedOutputByteBufferNano.java b/java/src/main/java/com/google/protobuf/nano/CodedOutputByteBufferNano.java
index 324a63f..53060da 100644
--- a/java/src/main/java/com/google/protobuf/nano/CodedOutputByteBufferNano.java
+++ b/java/src/main/java/com/google/protobuf/nano/CodedOutputByteBufferNano.java
@@ -300,6 +300,12 @@ public final class CodedOutputByteBufferNano {
       final int maxLengthVarIntSize = computeRawVarint32Size(value.length() * MAX_UTF8_EXPANSION);
       if (minLengthVarIntSize == maxLengthVarIntSize) {
         int oldPosition = buffer.position();
+        // Buffer.position, when passed a position that is past its limit, throws
+        // IllegalArgumentException, and this class is documented to throw
+        // OutOfSpaceException instead.
+        if (buffer.remaining() < minLengthVarIntSize) {
+          throw new OutOfSpaceException(oldPosition + minLengthVarIntSize, buffer.limit());
+        }
         buffer.position(oldPosition + minLengthVarIntSize);
         encode(value, buffer);
         int newPosition = buffer.position();
@@ -311,7 +317,10 @@ public final class CodedOutputByteBufferNano {
         encode(value, buffer);
       }
     } catch (BufferOverflowException e) {
-      throw new OutOfSpaceException(buffer.position(), buffer.limit());
+      final OutOfSpaceException outOfSpaceException = new OutOfSpaceException(buffer.position(),
+          buffer.limit());
+      outOfSpaceException.initCause(e);
+      throw outOfSpaceException;
     }
   }