Author: Jan Christoph Nordholz <hesso@pool.math.tu-berlin.de>
Description: Add lookup code for the creation time of each session.
 Requires digging in /proc/$pid and /proc/uptime, though, so it's
 definitely no candidate for the Beautiful C contest.
 .
 Affects screen's behaviour in the following situations:
 .
 * 'screen -ls' lists available sessions sorted chronologically
 * 'screen -RR' now picks the youngest session instead of an
   arbitrary one
 .
 Patch 3/3: implementation of actual new feature
Bug-Debian: https://bugs.debian.org/206572
Bug-Debian: https://bugs.debian.org/507817
Forwarded: not-yet

--- a/socket.c
+++ b/socket.c
@@ -137,16 +137,18 @@
   int sdirlen;
   int  matchlen = 0;
   char *name, *n;
-  int firsts = -1, sockfd;
-  char *firstn = NULL;
+  int sockfd;
   int nfound = 0, ngood = 0, ndead = 0, nwipe = 0, npriv = 0;
   int nperfect = 0;
+  time_t time_sysboot = time(NULL) - GetUptime();
   struct sent
     {
       struct sent *next;
       int mode;
+      int fd;
       char *name;
-    } *slist, **slisttail, *sent, *nsent;
+      time_t time_created;
+    } *slist, **slisttail, *sent, *nsent, *schosen;
 
   if (match)
     {
@@ -172,7 +174,7 @@
   if ((dirp = opendir(SockPath)) == 0)
     Panic(errno, "Cannot opendir %s", SockPath);
 
-  slist = 0;
+  slist = schosen = NULL;
   slisttail = &slist;
   while ((dp = readdir(dirp)))
     {
@@ -255,13 +257,16 @@
       debug("  store it.\n");
       if ((sent = (struct sent *)malloc(sizeof(struct sent))) == 0)
 	continue;
-      sent->next = 0;
       sent->name = SaveStr(name);
       sent->mode = mode;
+      sent->time_created = time_sysboot + SessionCreationTime(name);
+      for (slisttail = &slist; *slisttail; slisttail = &((*slisttail)->next)) {
+        if ((*slisttail)->time_created < sent->time_created) break;
+      }
+      sent->next = *slisttail;
       *slisttail = sent;
-      slisttail = &sent->next;
       nfound++;
-      sockfd = MakeClientSocket(0, *is_sock);
+      sent->fd = sockfd = MakeClientSocket(0, *is_sock);
 #ifdef USE_SETEUID
       /* MakeClientSocket sets ids back to eff */
       xseteuid(real_uid);
@@ -326,12 +331,17 @@
       ngood++;
       if (cmatch)
 	nperfect++;
-      if (fdp && (firsts == -1 || (cmatch && nperfect == 1)))
+      // prefer the current one if one of the following is true:
+      // - we had no previous hit
+      // - the current one has a later timestamp than our previous one, and we haven't found a perfect match yet
+      // - this one is the first perfect match
+      if (fdp && (!schosen ||
+		(schosen && schosen->time_created < sent->time_created && nperfect == 0) ||
+		(cmatch && nperfect == 1)))
 	{
-	  if (firsts != -1)
-	    close(firsts);
-	  firsts = sockfd;
-	  firstn = sent->name;
+	  if (schosen)
+	    close(schosen->fd);
+	  schosen = sent;
 	  debug("  taken.\n");
 	}
       else
@@ -359,36 +369,27 @@
 	}
       for (sent = slist; sent; sent = sent->next)
 	{
-	  switch (sent->mode)
+	  char timestr[64];
+	  if (sent->time_created == 0)
 	    {
-	    case 0700:
-	      printf("\t%s\t(Attached)\n", sent->name);
-	      break;
-	    case 0600:
-	      printf("\t%s\t(Detached)\n", sent->name);
-	      break;
+	      sprintf(timestr, "??" "?");
+	    }
+	  else
+	    {
+	      strftime(timestr, 64, "%x %X", localtime(&sent->time_created));
+	    }
+          printf("\t%s\t(%s)\t(%s)\n", sent->name, timestr,
+		(sent->mode == 0700) ? "Attached" :
+		(sent->mode == 0600) ? "Detached" :
 #ifdef MULTIUSER
-	    case 0701:
-	      printf("\t%s\t(Multi, attached)\n", sent->name);
-	      break;
-	    case 0601:
-	      printf("\t%s\t(Multi, detached)\n", sent->name);
-	      break;
+		(sent->mode == 0701) ? "Multi, attached" :
+		(sent->mode == 0601) ? "Multi, detached" :
 #endif
-	    case -1:
-	      /* No trigraphs here! */
-	      printf("\t%s\t(Dead ?%c?)\n", sent->name, '?');
-	      break;
-	    case -2:
-	      printf("\t%s\t(Removed)\n", sent->name);
-	      break;
-	    case -3:
-	      printf("\t%s\t(Remote or dead)\n", sent->name);
-	      break;
-	    case -4:
-	      printf("\t%s\t(Private)\n", sent->name);
-	      break;
-	    }
+		(sent->mode ==   -1) ? "Dead ??" "?" :
+		(sent->mode ==   -2) ? "Removed" :
+		(sent->mode ==   -3) ? "Remote or dead" :
+		(sent->mode ==   -4) ? "Private" :
+		"Unknown");
 	}
     }
   if (ndead && !quietflag)
@@ -399,10 +400,10 @@
       else
         Msg(0, m, ndead > 1 ? "s" : "", ndead > 1 ? "" : "es");	/* other args for nethack */
     }
-  if (firsts != -1)
+  if (schosen)
     {
-      sprintf(SockPath + sdirlen, "/%s", firstn);
-      *fdp = firsts;
+      sprintf(SockPath + sdirlen, "/%s", schosen->name);
+      *fdp = schosen->fd;
     }
   else
     SockPath[sdirlen] = 0;