Make registry's mergeKey fail if it cannot process regFileName

...so that regmerge fails for bad regfile arguments.  Add -v to the regmerge
calls in update-rdb.sh so that an error message is printed in case of failure.

Change-Id: I6613b9756b4e5628772541580938f6c80fd9bc9e
(cherry picked from commit 53fbd30b)

offapi/type_reference/update-rdb.sh

@@ -24,10 +24,10 @@ fi
 
 mkdir tmp
 for i in "$@"; do
-  "${OUTDIR_FOR_BUILD?}"/bin/regmerge tmp/out1.rdb /UCR \
+  "${OUTDIR_FOR_BUILD?}"/bin/regmerge -v tmp/out1.rdb /UCR \
     "${WORKDIR_FOR_BUILD?}"/UnoApiPartTarget/"${i%.idl}".urd
 done
-"${OUTDIR_FOR_BUILD?}"/bin/regmerge tmp/out2.rdb / \
+"${OUTDIR_FOR_BUILD?}"/bin/regmerge -v tmp/out2.rdb / \
   "${SRC_ROOT?}"/offapi/type_reference/types.rdb tmp/out1.rdb
 echo "sanity check diff:"
 diff <("${OUTDIR_FOR_BUILD?}"/bin/regview \

registry/source/registry.cxx

@@ -361,7 +361,7 @@ static RegError REGISTRY_CALLTYPE mergeKey(RegHandle hReg,
             return _ret;
 
         _ret = pReg->loadKey(pNewKey, regFileName, bWarnings, bReport);
-        if (_ret == REG_MERGE_ERROR || (_ret == REG_MERGE_CONFLICT && bWarnings))
+        if (_ret != REG_NO_ERROR && (_ret != REG_MERGE_CONFLICT || bWarnings))
         {
             if (pNewKey != pKey)
                 (void) pKey->closeKey(pNewKey);