reduce the number of error constants in use

src/ca/access.cpp

@@ -216,7 +216,7 @@ extern "C" int epicsShareAPI ca_search_and_connect (
     }
 
     if ( name_str == NULL || *name_str == '\0' ) {
-        return ECA_EMPTYSTR;
+        return ECA_BADSTR;
     }
 
     oldChannelNotify *pChanNotify = new oldChannelNotify ( *pcac, name_str, conn_func, puser );
@@ -587,7 +587,7 @@ extern "C" int epicsShareAPI ca_add_masked_array_event (
     {
         return ECA_ALLOCMEM;
     }
-    catch ( cacChannel::msgBodyCacheTooSmall ) {
+    catch ( cacChannel::msgBodyCacheTooSmall & ) {
         return ECA_TOLARGE;
     }
     catch ( ... )

src/rsrv/camessage.c

@@ -1621,7 +1621,9 @@ LOCAL int event_add_action (caHdrLargeArray *mp, void *pPayload, struct client *
         log_header ("no memory to add subscription to db", 
             client, mp, pPayload, 0);
         SEND_LOCK(client);
-        send_err (mp, ECA_ADDFAIL, client, RECORD_NAME(&pciu->addr));
+        send_err (mp, ECA_ALLOCMEM, client, 
+            "subscription install into record %s failed", 
+            RECORD_NAME(&pciu->addr));
         SEND_UNLOCK(client);
         return RSRV_ERROR;
     }