improve exception if bsn not set npe->ise


git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@994997 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/sigil/common/core/src/org/apache/felix/sigil/common/config/BldConverter.java b/sigil/common/core/src/org/apache/felix/sigil/common/config/BldConverter.java
index 84477c5..5e647e8 100644
--- a/sigil/common/core/src/org/apache/felix/sigil/common/config/BldConverter.java
+++ b/sigil/common/core/src/org/apache/felix/sigil/common/config/BldConverter.java
@@ -278,7 +278,8 @@
         String idBsn = id != null ? id : ids.get(0);
         String oldBsn = config.getString(id, BldConfig.S_SYM_NAME);
         String bsn = info.getSymbolicName();
-
+        if (bsn == null) throw new IllegalArgumentException("Missing bundle symbolic name");
+        
         if (!bsn.equals(idBsn) || oldBsn != null)
             config.setString(id, BldConfig.S_SYM_NAME, bsn);