try to fix a couple more core dumps.

RdbList.cpp

@@ -1686,9 +1686,12 @@ void RdbList::merge_r ( RdbList **lists         ,
 	// did they call prepareForMerge()?
 	if ( m_mergeMinListSize == -1 ) {
 		log(LOG_LOGIC,"db: rdblist: merge_r: prepareForMerge() not "
-		    "called.");
+		    "called. ignoring error and returning emtpy list.");
+		// this happens if we nuke doledb during a merge of it. it
+		// is just bad timing
+		return;
 		// save state and dump core, sigBadHandler will catch this
-		char *p = NULL;	*p = 0;
+		//char *p = NULL;	*p = 0;
 	}
 	// already there?
 	if ( minRecSizes >= 0 && m_listSize >= minRecSizes ) return;

Tagdb.cpp

@@ -2603,7 +2603,7 @@ bool Msg8a::getTagRec ( Url   *url ,
 	// . msge0 passes this in as NULL an expects us to figure it out
 	// . if site was NULL that means we guess it. default to hostname
 	//   unless in a recognized for like /~mwells/
-	if ( ! site ) {
+	if ( ! site || siteLen <= 0 ) {
 		SiteGetter sg;
 		sg.getSite ( url->getUrl() ,
 			     NULL , // tagrec
@@ -2622,11 +2622,19 @@ bool Msg8a::getTagRec ( Url   *url ,
 
 	// if provided site was NULL and not of a ~mwells type of form
 	// then default it to hostname
-	if ( ! site ) {
+	if ( ! site || siteLen <= 0 ) {
 		site    = url->getHost();
 		siteLen = url->getHostLen();
 	}
 
+	// if still the host is bad, then forget it
+	if ( ! site || siteLen <= 0 ) {
+		log("tagdb: got bad url with no site");
+		m_errno = EBADURL;
+		g_errno = EBADURL;
+		return true;
+	}
+
 	// temp null terminate it
 	char c = site[siteLen];
 	site[siteLen] = '\0';