Weechat plugin to sort your buffers alphabetically (which results in grouping them by server) and correct the buffer numbering. ibuffer has a sort mode, but it does not correct the numbering. has the hook for channel joins

sort_buffs.tcl

weechat::register "sort_buffs" "FlashCode" "0.1" "GPL3" "sorts buffers" "" ""                                                                                  
                                                                                                                                                               
                                                                                                                                                               
proc sortbuffs {data signal signal_data} {                                                                                                                     
    set bufflist []                                                                                                                                            
                                                                                                                                                               
    set infolist [weechat::infolist_get "buffer" "" ""]                                                                                                        
                                                                                                                                                               
    while { [weechat::infolist_next $infolist] } {                                                                                                             
        set name [weechat::infolist_string $infolist "name" ]                                                                                                  
        regsub "\\." $name "," name                                                                                                                            
        set bufflist [linsert $bufflist [llength $bufflist] $name]                                                                                             
    }                                                                                                                                                          
                                                                                                                                                               
    set bufflist [lsort -decreasing -dictionary $bufflist]                                                                                                     
                                                                                                                                                               
    set i 0                                                                                                                                                    
    foreach b $bufflist {                                                                                                                                      
        incr i                                                                                                                                                 
        set cur [weechat::info_get "irc_buffer" $b]                                                                                                            
        weechat::buffer_set $cur "number" $i                                                                                                                   
    }                                                                                                                                                          
    return 1                                                                                                                                                   
}                                                                                                                                                              
                                                                                                                                                               
weechat::hook_signal "*,irc_in2_join" sortbuffs ""