Re-open closed message base for commands to use selected/open base

Should fix issue #790

exec/nntpservice.js

@@ -534,6 +534,11 @@ while(client.socket.is_connected && !quit) {
 				writeln("412 read permission to newsgroup denied");
 				break;
 			}
+			if(!msgbase.is_open && !msgbase.open()) {
+				log(LOG_ERR, "Error " + msgbase.error + " opening " + msgbase.file);
+				writeln("503 unable to re-open message base");
+				break;
+			}
 			var first, last;
 			if(cmd[1]==undefined || cmd[1].length==0)
 				first=last=current_article;
@@ -583,6 +588,11 @@ while(client.socket.is_connected && !quit) {
 				writeln("412 read permission to newsgroup denied");
 				break;
 			}
+			if(!msgbase.is_open && !msgbase.open()) {
+				log(LOG_ERR, "Error " + msgbase.error + " opening " + msgbase.file);
+				writeln("503 unable to re-open message base");
+				break;
+			}
 			writeln("221 Header follows");
 			var first, last;
 			if(cmd[2].indexOf('-')>=0)	{ /* range */
@@ -682,6 +692,11 @@ while(client.socket.is_connected && !quit) {
 				writeln("420 no current article has been selected");
 				break;
 			}
+			if(!msgbase.is_open && !msgbase.open()) {
+				log(LOG_ERR, "Error " + msgbase.error + " opening " + msgbase.file);
+				writeln("503 unable to re-open message base");
+				break;
+			}
 
 			hdr=null;
 			body=null;