patches written by Steve Kemp, it adds two new functionalities to the sidebar,
so only the mailbox with new messages will be shown (and/or) selected
See Debian bug http://bugs.debian.org/532510

--- a/OPS
+++ b/OPS
@@ -184,3 +184,5 @@
 OP_SIDEBAR_NEXT "go down to next mailbox"
 OP_SIDEBAR_PREV "go to previous mailbox"
 OP_SIDEBAR_OPEN "open hilighted mailbox"
+OP_SIDEBAR_NEXT_NEW "go down to next mailbox with new mail"
+OP_SIDEBAR_PREV_NEW "go to previous mailbox with new mail"
--- a/curs_main.c
+++ b/curs_main.c
@@ -2236,6 +2236,8 @@
       case OP_SIDEBAR_SCROLL_DOWN:
       case OP_SIDEBAR_NEXT:
       case OP_SIDEBAR_PREV:
+      case OP_SIDEBAR_NEXT_NEW:
+      case OP_SIDEBAR_PREV_NEW:
         scroll_sidebar(op, menu->menu);
         break;
       default:
--- a/functions.h
+++ b/functions.h
@@ -173,6 +173,10 @@
  { "sidebar-scroll-down",	OP_SIDEBAR_SCROLL_DOWN, NULL },
  { "sidebar-next",		OP_SIDEBAR_NEXT, NULL },
  { "sidebar-prev",		OP_SIDEBAR_PREV, NULL },
+ { "sidebar-next-new", OP_SIDEBAR_NEXT_NEW, NULL},
+ { "sidebar-prev-new", OP_SIDEBAR_PREV_NEW, NULL},
+ { "sidebar-next-new", OP_SIDEBAR_NEXT_NEW, NULL},
+ { "sidebar-prev-new", OP_SIDEBAR_PREV_NEW, NULL},
  { "sidebar-open",		OP_SIDEBAR_OPEN, NULL },
   { NULL,			0,				NULL }
 };
--- a/init.h
+++ b/init.h
@@ -1956,6 +1956,11 @@
   {"sidebar_delim", DT_STR, R_BOTH, UL &SidebarDelim, "|"},
   /*
   ** .pp
+  ** Show only new mail in the sidebar.
+  */
+  {"sidebar_newmail_only", DT_BOOL, R_BOTH, OPTSIDEBARNEWMAILONLY, "no" },
+  /*
+  ** .pp
   ** This specifies the delimiter between the sidebar (if visible) and
   ** other screens.
   */
--- a/mutt.h
+++ b/mutt.h
@@ -518,6 +518,8 @@
   OPTDONTHANDLEPGPKEYS,	/* (pseudo) used to extract PGP keys */
   OPTUNBUFFEREDINPUT,   /* (pseudo) don't use key buffer */
 
+  OPTSIDEBARNEWMAILONLY,
+
   OPTMAX
 };
 
--- a/pager.c
+++ b/pager.c
@@ -2756,6 +2756,8 @@
       case OP_SIDEBAR_SCROLL_DOWN:
       case OP_SIDEBAR_NEXT:
       case OP_SIDEBAR_PREV:
+      case OP_SIDEBAR_NEXT_NEW:
+      case OP_SIDEBAR_PREV_NEW:
 	scroll_sidebar(ch, MENU_PAGER);
  	break;
 
--- a/sidebar.c
+++ b/sidebar.c
@@ -261,8 +261,20 @@
 			SETCOLOR(MT_COLOR_NEW);
 		else if ( tmp->msg_flagged > 0 )
 		        SETCOLOR(MT_COLOR_FLAGGED);
-		else
-			SETCOLOR(MT_COLOR_NORMAL);
+		else {
+                  /* make sure the path is either:
+                     1.  Containing new mail.
+                     2.  The inbox.
+                     3.  The current box.
+                   */
+                  if ((option (OPTSIDEBARNEWMAILONLY)) &&
+                      ( (tmp->msg_unread <= 0)  &&
+                        ( tmp != Incoming ) &&
+                        ( strcmp( tmp->path, Context->path ) != 0 ) ) )
+                    continue;
+                  else
+                    SETCOLOR(MT_COLOR_NORMAL);
+                }
 
 		move( lines, 0 );
 		if ( Context && !strcmp( tmp->path, Context->path ) ) {
@@ -320,6 +332,29 @@
 	return 0;
 }
 
+BUFFY * exist_next_new()
+{
+       BUFFY *tmp = CurBuffy;
+       if(tmp == NULL) return NULL;
+       while (tmp->next != NULL)
+       {
+              tmp = tmp->next;
+               if(tmp->msg_unread) return tmp;
+       }
+       return NULL;
+}
+
+BUFFY * exist_prev_new()
+{
+       BUFFY *tmp = CurBuffy;
+       if(tmp == NULL) return NULL;
+       while (tmp->prev != NULL)
+       {
+               tmp = tmp->prev;
+               if(tmp->msg_unread) return tmp;
+       }
+       return NULL;
+}
 
 void set_buffystats(CONTEXT* Context)
 {
@@ -336,18 +371,33 @@
 
 void scroll_sidebar(int op, int menu)
 {
+        BUFFY *tmp;
         if(!SidebarWidth) return;
         if(!CurBuffy) return;
 
 	switch (op) {
 		case OP_SIDEBAR_NEXT:
+                if (!option (OPTSIDEBARNEWMAILONLY)) {
 			if ( CurBuffy->next == NULL ) return;
 			CurBuffy = CurBuffy->next;
 			break;
+                }
+                case OP_SIDEBAR_NEXT_NEW:
+                        if ( (tmp = exist_next_new()) == NULL)
+                                return;
+                        else CurBuffy = tmp;
+                        break;
 		case OP_SIDEBAR_PREV:
+                 if (!option (OPTSIDEBARNEWMAILONLY)) {
 			if ( CurBuffy->prev == NULL ) return;
 			CurBuffy = CurBuffy->prev;
 			break;
+                }
+                case OP_SIDEBAR_PREV_NEW:
+                       if ( (tmp = exist_prev_new()) == NULL)
+                               return;
+                       else CurBuffy = tmp;
+                       break;
 		case OP_SIDEBAR_SCROLL_UP:
 			CurBuffy = TopBuffy;
 			if ( CurBuffy != Incoming ) {