Fixed reallocation of buffer in bson

src/bson.c

@@ -459,7 +459,7 @@ void bson_append64(bson_buffer * b, const void * data){
 int bson_ensure_space( bson_buffer * b, const int bytesNeeded ){
     int pos = b->cur - b->buf;
     char * orig = b->buf;
-    int new_size;
+    unsigned int new_size;
 
     if (b->finished) {
         b->err = BSON_OBJECT_FINISHED;
@@ -469,17 +469,16 @@ int bson_ensure_space( bson_buffer * b, const int bytesNeeded ){
     if (pos + bytesNeeded <= b->bufSize)
         return BSON_OK;
 
+	if( b->bufSize + bytesNeeded > INT_MAX )
+	{
+		b->err = BSON_SIZE_OVERFLOW;
+		return BSON_ERROR;
+	}
+	
     new_size = 1.5 * (b->bufSize + bytesNeeded);
-
-    if( new_size < b->bufSize ) {
-        if( ( b->bufSize + bytesNeeded ) < INT_MAX )
-            new_size = INT_MAX;
-        else {
-            b->err = BSON_SIZE_OVERFLOW;
-            return BSON_ERROR;
-        }
-    }
-
+	if( (new_size > INT_MAX) && (b->bufSize + bytesNeeded < INT_MAX) )
+		new_size = INT_MAX;
+	
     b->buf = realloc(b->buf, new_size);
     if (!b->buf)
         bson_fatal_msg(!!b->buf, "realloc() failed");