#!/bin/sh
# Tcl ignores the next line \
exec wish "$0" -- "${1+$@}"

# Copyright (C) 1999-2002 Paul Mackerras.  All rights reserved.
# This program is free software; it may be used, copied, modified
# and distributed under the terms of the GNU General Public Licence,
# either version 2, or (at your option) any later version.

set nofilecmp [catch {load libfilecmp.so.0.0}]
set rcsflag {}
set diffbflag {}
set diffBflag {}
set diffiflag {}
set diffwflag {}
set diffdflag {}
set ctxlines 3
set showsame 0
set underlinetabs 0
set bitkeeper 0
set bkgetmode " "
set redisp_immed 1
set diffnewfirst 0
set nukefiles {*.o *~ *.orig CVS *.a *.link *.old *.save .depend .*.flags SCCS}

set agecolors(dir) {black white}
set agecolors(0) {black}
set agecolors(1) {black green}
set agecolors(2) {black green red}
set agecolors(3) {black green yellow red}
set agecolors(4) {black green yellow orange red}
set agecolors(5) {black green #d0ff00 yellow orange red}

set bgcolors(2) {x green "#ff8080"}
set bgcolors(3) {x green yellow "#ff8080"}
set bgcolors(4) {x green yellow orange "#ff8080"}
set bgcolors(5) {x green "#e0ff90" yellow orange "#ff8080"}

set linespc 15
set numlines 20
set canvy0 0
set canvy 0
set canvx 0
set blotw 12
set bloth 12
set blotspc 15

proc ignorefile pat {
    global nukefiles
    if {$pat == "!"} {
	set nukefiles {}
    } else {
	lappend nukefiles $pat
    }
}

catch {source ~/.dirdiff}

proc usage {} {
    puts stderr {Usage: dirdiff [options]... dir1 dir2 ...

Options:
   -a, --all		don't exclude any files
   -o, --only pattern	only process files matching pattern
   -I, --ignore pattern	don't process files matching pattern
   -r, --rcs		ignore differences in RCS strings
   -t, --bktag		ignore differences in Bitkeeper strings
   -c, --context num	set number of lines of context to show
   -b, -w, -B, -i, -d	pass these on to diff(1)
   -S			show files that are the same in the file list
   -K			Bitkeeper support

Note: dirdiff needs to be able to load the libfilecmp.so.0.0 shared library
for the -r or -t flags to work.}
}

if {![info exists dirs]} {
    global onlyfiles ctxlines showsame
    set dirs {}
    set ok 1
    set argc [llength $argv]
    set moreopts 1
    for {set i 0} {$i < $argc} {incr i} {
	set arg [lindex $argv $i]
	if {$moreopts && [string range $arg 0 0] == "-"} {
	    switch -regexp -- $arg {
		"--" {
		    set moreopts 0
		}
		"-a|--all" {
		    set nukefiles {}
		}
		"-o|--only" {
		    incr i
		    if {$i < $argc} {
			lappend onlyfiles [lindex $argv $i]
			set nukefiles {}
		    } else {
			puts stderr "no argument given to $arg option"
			set ok 0
		    }
		}
		"-I|--ignore" {
		    incr i
		    if {$i < $argc} {
			ignorefile [lindex $argv $i]
		    } else {
			puts stderr "no argument given to $arg option"
			set ok 0
		    }
		}
		"-r|--rcs" {
		    if $nofilecmp {
			puts stderr "can't use $arg: libfilecmp.so.0.0 couldn't be loaded"
			set ok 0
		    }
		    set rcsflag "-rcs"
		}
		"-t|--bktag" {
		    if $nofilecmp {
			puts stderr "can't use $arg: libfilecmp.so.0.0 couldn't be loaded"
			set ok 0
		    }
		    set rcsflag "-bk"
		}
		"-c|--context" {
		    incr i
		    if {$i < $argc} {
			set ctxlines [lindex $argv $i]
		    } else {
			puts stderr "no argument given to $arg option"
			set ok 0
		    }
		}
		"-b" { set diffbflag "-b" }
		"-w" { set diffwflag "-w" }
		"-B" { set diffBflag "-B" }
		"-i" { set diffiflag "-i" }
		"-d" { set diffdflag "-d" }
		"-S" { set showsame 1 }
		"-K" { set bitkeeper 1 }
		"-h|--help" {
		    usage
		    exit 0
		}
		default {
		    puts stderr "unrecognized option $arg"
		    set ok 0
		}
	    }
	} elseif {$arg != {}} {
	    lappend dirs [string trimright $arg /]
	}
    }
    if {$ok && [llength $dirs] == 0} {
	usage
	set ok 0
    }
    if {!$ok} {exit 1}
    set doit 1
}

proc addfiles {sd} {
    global dirs stat onlyfiles statinfo fserial nextserial
    global filetype filesize filetime
    foreach d $dirs {
	foreach f [lsort [glob -nocomplain $d/$sd* $d/$sd.*]] {
	    set fs $sd[file tail $f]
	    set wantim 0
	    if [notnuked $fs] {
		if {[catch {file lstat $f stat}] == 0} {
		    if {$stat(type) == "file"} {
			if [info exists onlyfiles] {
			    foreach o $onlyfiles {
				if [string match $o $fs] {
				    set wantim 1
				    break
				}
			    }
			} else {
			    set wantim 1
			}
		    } elseif {$stat(type) == "directory"} {
			append fs /
			set wantim 1
		    }
		}
	    }
	    if {$wantim} {
		if {![info exists files($fs)]} {
		    set fserial($fs) [incr nextserial]
		    set files($fs) 1
		}
		set filetype($f) $stat(type)
		set filesize($f) $stat(size)
		set filetime($f) $stat(mtime)
	    }
#	    update
	}
    }
    return [lsort [array names files]]
}

# Called to re-lstat a given file across all directories
proc updatefileinfo {f} {
    global dirs filetype filesize filetime

    foreach d $dirs {
	set df [joinname $d [string trimright $f /]]
	if {[catch {file lstat $df stat}] == 0} {
	    set filetype($df) $stat(type)
	    set filesize($df) $stat(size)
	    set filetime($df) $stat(mtime)
	} else {
	    catch {unset filetype($df)}
	}
    }
}

# Returns 1 if we are interested in this file, i.e. if it isn't
# matched by something in the exclude list
proc notnuked {f} {
    global nukefiles
    set ft [file tail $f]
    if {$ft == "." || $ft == ".."} {
	return 0
    }
    foreach n $nukefiles {
	if {[string match $n $f] || [string match $n $ft]} {
	    return 0
	}
    }
    return 1
}

proc joinname {dir f} {
    global filemode
    if {$filemode} {
	return $dir
    }
    return [file join $dir $f]
}

proc fileisa {f t} {
    global filetype
    return [expr {[info exists filetype($f)] && $filetype($f) == $t}]
}

proc diffages {f showsame} {
    global dirs nofilecmp rcsflag filesize filetime
    set numgroups 0
    set notexist {}
    set doesexist {}
    foreach d $dirs {
	set sameas($d) {}
	set group($d) 0
	set fname [joinname $d $f]
	if {![fileisa $fname "file"]} {
	    set fd [file dirname $fname]
	    if {[file dirname $f] == "." || [fileisa $fd "directory"]} {
		lappend notexist $d
	    }
	} else {
	    lappend doesexist $d
	    set fsize($d) $filesize($fname)
	    set fmtime($d) $filetime($fname)
	    foreach d2 $dirs {
		if {$d2 == $d} break
		if {$sameas($d2) != "" || $group($d2) == 0} continue
		if {$fsize($d) == $fsize($d2) \
			&& $fmtime($d) == $fmtime($d2)} {
		    set notsame 0
		} elseif {$rcsflag != "" || $fsize($d) == $fsize($d2)} {
		    set fname2 [joinname $d2 $f]
		    if $nofilecmp {
			set notsame [catch {exec cmp -s $fname $fname2}]
		    } else {
			set same 0
			catch {
			    set same [eval filecmp $rcsflag $fname $fname2]
			}
			set notsame [expr !$same]
		    }
		} else {
		    set notsame 1
		}
		if {$notsame == 0} {
		    set sameas($d) $d2
		    set g $group($d2)
		    set group($d) $g
		    lappend groupelts($g) $d
		    if {$fmtime($d) > $gmtime($g)} {
			set gmtime($g) $fmtime($d)
		    }
		    break
		}
	    }
	    if {$sameas($d) == ""} {
		incr numgroups
		set group($d) $numgroups
		set groupelts($numgroups) $d
		set gmtime($numgroups) $fmtime($d)
	    }
	}
    }
    if {!$showsame && $numgroups == 1 && $notexist == ""} {
	return {}
    }
    set glist {}
    for {set g 1} {$g <= $numgroups} {incr g} {
	lappend glist [list [format "%.8x" $gmtime($g)] $g]
    }
    set grank(0) 0
    set rank 1
    foreach xx [lsort -decreasing $glist] {
	set g [lindex $xx 1]
	set grank($g) $rank
	incr rank
    }
    set res {}
    foreach d $dirs {
	lappend res $grank($group($d))
    }
    return [list $numgroups $res]
}

proc subdirgroups {sd} {
    global dirs
    set nummiss 0
    set groups {}
    foreach d $dirs {
	set fn [joinname $d $sd]
	if {![fileisa $fn "directory"]} {
	    set pd [file dirname $sd]
	    lappend groups 0
	    set fnp [joinname $d $pd]
	    if {$pd == "." || [fileisa $fnp "directory"]} {
		incr nummiss
	    }
	} else {
	    lappend groups 1
	}
    }
    if {$nummiss == 0} {
	return {}
    }
    return [list dir $groups]
}

set stringx 8

proc initcanv {} {
    global canvw canvx canvy canvy0 linespc stringx
    global dirs arroww blotspc blotw ycoord
    $canvw delete all
    $canvw yview moveto 0
    $canvw conf -scrollregion {0 0 0 1}
    catch {unset ycoord}
    set canvy $canvy0
    if {![info exists arroww]} {
	set stringx [expr $blotspc + 8]
	return
    }
    set numdirs [llength $dirs]
    set stringx [expr $numdirs * $blotspc + 8]
    $arroww delete all
    set arrowh [expr ($numdirs+1) * $linespc]
    $arroww conf -height $arrowh
    set y 0
    set yoff [expr $linespc / 2]
    set x [expr $canvx + 3 + ($blotw / 2)]
    set x2 [expr $stringx - 3]
    foreach d $dirs {
	set y2 [expr $y + $yoff]
	set t [$arroww create line $x $arrowh $x $y2 $x2 $y2 \
		-width 2 -arrow first]
	$arroww addtag arrows withtag $t
	set t [$arroww create text $stringx $y -text $d -anchor nw]
	$arroww addtag strings withtag $t
	incr y $linespc
	incr x $blotspc
    }
}

proc addcline {blots str} {
    global canvy canvx linespc stringx blotw bloth blotspc canvw ycoord
    set x [expr $canvx+1]
    set y [expr $canvy+1]
    foreach b $blots {
	set t [$canvw create rectangle $x $y [expr $x+$blotw] \
		[expr $y+$bloth] -fill $b]
	$canvw addtag blots withtag $t
	incr x $blotspc
    }
    set t [$canvw create text $stringx $canvy -anchor nw -text $str]
    $canvw addtag strings withtag $t
    set ycoord($str) $canvy
    incr canvy $linespc
    set vis [lindex [$canvw yview] 1]
    $canvw conf -scrollregion "0 0 0 $canvy"
    if {$vis >= 1.0} {
	$canvw yview moveto 1
    }
}

proc displine {groups name} {
    global agecolors
    set ng [lindex $groups 0]
    set cols $agecolors($ng)
    set blots {}
    foreach g [lindex $groups 1] {
	lappend blots [lindex $cols $g]
    }
    addcline $blots $name
}

proc dispfilelines {groups} {
    global agecolors dirs
    set ng [lindex $groups 0]
    set cols $agecolors($ng)
    set n 0
    foreach g [lindex $groups 1] {
	addcline [lindex $cols $g] [lindex $dirs $n]
	incr n
    }
}

proc ruleoff {stopped} {
    global canvw canvy linespc ruletype
    set y [expr $canvy + $linespc/2]
    set color black
    if {$stopped} {set color red}
    $canvw create line 0 $y [$canvw cget -width] $y -width 2 -fill $color
    incr canvy $linespc
    set vis [lindex [$canvw yview] 1]
    $canvw conf -scrollregion "0 0 0 $canvy"
    if {$vis >= 1.0} {
	$canvw yview moveto 1
    }
    set ruletype $stopped
}

proc updatecline {si di f} {
    global ycoord canvw blotspc bloth blotw groups
    global filemode dirs
    if {$filemode} {
	set fs [lindex $dirs $si]
	set fd [lindex $dirs $di]
	if {![info exists ycoord($fs)] || ![info exists ycoord($fd)]} return
	set ys [expr $ycoord($fs) + 2]
	set yd [expr $ycoord($fd) + 2]
	set xs 2
	set xd 2
    } else {
	if {![info exists ycoord($f)]} return
	set ys [expr $ycoord($f) + 2]
	set yd $ys
	set xs [expr $si * $blotspc + 2]
	set xd [expr $di * $blotspc + 2]
    }
    set ts [$canvw find overlapping $xs $ys \
	    [expr $xs+$blotw-2] [expr $ys+$bloth-2]]
    set td [$canvw find overlapping $xd $yd \
	    [expr $xd+$blotw-2] [expr $yd+$bloth-2]]
    if {$ts != "" && $td != ""} {
	$canvw itemconf $td -fill [$canvw itemcget $ts -fill]
    }
    set ng [lindex $groups($f) 0]
    set g [lindex $groups($f) 1]
    set groups($f) [list $ng [lreplace $g $di $di [lindex $g $si]]]
}

proc refreshcline {f} {
    global ycoord canvw blotspc bloth blotw groups
    global agecolors
    if {![info exists ycoord($f)]} return
    set y [expr $ycoord($f) + 2]
    set ng [lindex $groups($f) 0]
    set cols $agecolors($ng)
    set x 2
    foreach g [lindex $groups($f) 1] {
	set t [$canvw find overlapping $x $y \
		[expr $x+$blotw-2] [expr $y+$bloth-2]]
	if {$t != ""} {
	    $canvw itemconf $t -fill [lindex $cols $g]
	}
	incr x $blotspc
    }
}

proc makepatchmenu {base} {
    global dirs
    menu $base.p -tearoff 0
    foreach d1 $dirs {
	foreach d2 $dirs {
	    if {$d1 == $d2} continue
	    $base.p add command -label "$d1 to $d2" \
		    -command "makepatch $d1 $d2"
	}
    }
    $base add cascade -label "Make patch" -menu $base.p
}

proc maketouchmenu {base} {
    global dirs
    menu $base.t -tearoff 0
    foreach d $dirs {
	$base.t add command -label $d -command "touchfiles $d"
    }
    $base add cascade -label "Touch" -menu $base.t
}

proc makebkgetmenu {base} {
    global dirs bitkeeper
    menu $base.g -tearoff 0
    foreach d $dirs {
	$base.g add command -label $d -command "bkgetfiles $d"
    }
    $base add cascade -label "BK get" -menu $base.g \
	    -state [expr {$bitkeeper? "normal": "disabled"}]
}

proc makewins {} {
    global canvw numlines linespc arroww diffbut copybut filelabel nofilecmp
    global filemode dirs dirinterest

    # Make the menu bar and the menu items in it
    frame .bar -relief raised -border 2
    pack .bar -side top -fill x
    menubutton .bar.file -text File -menu .bar.file.m -padx 10 -pady 1
    menu .bar.file.m -tearoff 0
    .bar.file.m add command -label "Rediff" -command rediff
    if {!$filemode} {
	.bar.file.m add command -label "Redisplay" -command redisplay
    }
    makepatchmenu .bar.file.m
    maketouchmenu .bar.file.m
    makebkgetmenu .bar.file.m
    .bar.file.m add command -label "Stop" -command "set stopped 1"
    .bar.file.m add separator
    .bar.file.m add command -label "Quit" -command "set stopped 1; destroy ."
    pack .bar.file -side left
    set diffbut .bar.diff
    menubutton $diffbut -text Diff -menu $diffbut.m -padx 10 -pady 1
    menu $diffbut.m -tearoff 0
    $diffbut.m add command -label "All" -command difffiles
    pack $diffbut -side left
    set copybut .bar.copy
    menubutton $copybut -text Copy -menu $copybut.m -padx 10 -pady 1
    menu $copybut.m -tearoff 0
    pack $copybut -side left

    # make the filename display bar
    if {!$filemode} {
	frame .file -relief sunk -border 2
	set filelabel .file.name
	label $filelabel -padx 7 -text "File: "
	pack $filelabel -side left -fill x
	pack .file -side top -fill x
    }

    # make the frame containing the 2 canvases (one for the top section
    # containing the directory names, one for the files) and the scrollbar
    # in file mode the top section is omitted
    frame .cf
    if {$filemode} {
	set numlines [llength $dirs]
    }
    canvas .cf.c -height [expr $numlines * $linespc] \
	    -yscrollincr $linespc -yscrollcommand ".csb set"
    set canvw .cf.c
    if {!$filemode} {
	canvas .cf.d -height [expr 3 * $linespc]
	set arroww .cf.d
	pack .cf.d -side top -fill x
    }
    pack .cf.c -side bottom -fill both -expand 1
    scrollbar .csb -command "$canvw yview"
    pack .csb -side right -fill y
    pack .cf -side left -fill both -expand 1

    # set up event bindings on the main canvas
    bind $canvw <1> {selcanvline %x %y 0}
    bind $canvw <Shift-1> {selcanvline %x %y 1}
    bind $canvw <B1-Motion> {selcanvline %x %y 2}
    bind $canvw <ButtonRelease-1> {selcurfile}
    bind $canvw <ButtonRelease-4> "$canvw yview scroll -5 u"
    bind $canvw <ButtonRelease-5> "$canvw yview scroll 5 u"
    bind $canvw <2> "$canvw scan mark 0 %y"
    bind $canvw <B2-Motion> "$canvw scan dragto 0 %y"
    bind $canvw <Double-Button-1> "set doubleclick 1; showsomediff 0"
    $canvw conf -scrollregion {0 0 0 1}
    if {!$filemode} {
	bind . N "diffnextfile 1"
	bind . P "diffnextfile -1"
    }
    bind . C copydifffile
    bind . <Key-Return> "showsomediff 0"
    bind . <Key-Prior> "$canvw yview scroll -1 p"
    bind . <Key-Next> "$canvw yview scroll 1 p"
    bind . <Key-Delete> "$canvw yview scroll -1 p"
    bind . <Key-BackSpace> "$canvw yview scroll -1 p"
    bind . <Key-space> "$canvw yview scroll 1 p"
    bind . <Key-Up> "$canvw yview scroll -1 u"
    bind . <Key-Down> "$canvw yview scroll 1 u"
    bind . Q "set stopped 1; destroy ."

    # Options menu
    global rcsflag diffiflag diffwflag diffbflag diffBflag diffdflag
    global bitkeeper
    menubutton .bar.options -text Options -menu .bar.options.m -padx 10 -pady 1
    menu .bar.options.m -tearoff 0
    pack .bar.options -side left
    .bar.options.m add radiobutton -label "Literal comparison" \
	    -variable rcsflag -value " " \
	    -state [expr {$nofilecmp? "disabled": "normal"}]
    .bar.options.m add radiobutton -label "Ignore differences in RCS strings" \
	    -variable rcsflag -value "-rcs" \
	    -state [expr {$nofilecmp? "disabled": "normal"}]
    .bar.options.m add radiobutton -label "Ignore differences in BK tags" \
	    -variable rcsflag -value "-bk" \
	    -state [expr {$nofilecmp? "disabled": "normal"}]
    .bar.options.m add checkbutton -label "Show files that are identical" \
	    -variable showsame
    .bar.options.m add checkbutton -label "Bitkeeper support" \
	    -variable bitkeeper \
	    -command bkchange
    menu .bar.options.m.bkmode -tearoff 0
    .bar.options.m.bkmode add radiobutton -label "Expand keywords" \
	    -variable bkgetmode -value " "
    .bar.options.m.bkmode add radiobutton -label "Don't expand keywords" \
	    -variable bkgetmode -value "k"
    .bar.options.m.bkmode add radiobutton -label "Check out for editing" \
	    -variable bkgetmode -value "e"
    .bar.options.m add cascade -label "BK get mode" \
	    -menu .bar.options.m.bkmode \
	    -state [expr {$bitkeeper? "normal": "disabled"}]
    .bar.options.m add checkbutton -label "Redisplay immediately" \
	    -variable redisp_immed
    .bar.options.m add command -label "Excluded files..." -command exclfilelist
    .bar.options.m add command -label "Diff options..." -command diffoptions
    .bar.options.m add command -label "Save" -command saveoptions

    .bar.options.m add separator
    set i 0
    foreach d $dirs {
	set dirinterest($i) 1
	.bar.options.m add checkbutton -label "Show $d" \
		-variable dirinterest($i) -command maybe_redisplay
	incr i
    }

    # Help menu
    menubutton .bar.help -text Help -menu .bar.help.m -padx 10 -pady 1
    menu .bar.help.m -tearoff 0
    pack .bar.help -side right
    .bar.help.m add command -label "About dirdiff" -command about
    .bar.help.m add command -label "Show help text" -command helptext
}

proc bkchange {} {
    global bitkeeper
    set state [expr {$bitkeeper? "normal": "disabled"}]
    .bar.options.m entryconf "BK*" -state $state
    .bar.file.m entryconf "BK*" -state $state
}

proc about {} {
    set w .about
    if {[winfo exists $w]} {
	raise $w
	return
    }
    toplevel $w
    wm title $w "About dirdiff"
    message $w.m -text {
Dirdiff version 1.6

Copyright  1999-2001 Paul Mackerras

Use and redistribute under the terms of the GNU General Public License

(CVS $Revision: 1.43 $)} \
	    -justify center -aspect 400
    pack $w.m -side top -fill x -padx 20 -pady 20
    button $w.ok -text Close -command "destroy $w"
    pack $w.ok -side bottom
}

proc helptext {} {
    set w .help
    if {[winfo exists $w]} {
	raise $w
	return
    }
    toplevel $w
    wm title $w "Dirdiff help"
    text $w.t -font {Times -14} -yscrollcommand "$w.sb set" -wrap word
    scrollbar $w.sb -command "$w.t yview"
    pack $w.sb -side right -fill y
    pack $w.t -side left -fill both -expand 1
    bind $w <Key-Prior> "$w.t yview scroll -1 p"
    bind $w <Key-BackSpace> "$w.t yview scroll -1 p"
    bind $w <Key-Delete> "$w.t yview scroll -1 p"
    bind $w b "$w.t yview scroll -1 p"
    bind $w B "$w.t yview scroll -1 p"
    bind $w <Key-Up> "$w.t yview scroll -1 u"
    bind $w <Key-Down> "$w.t yview scroll 1 u"
    bind $w d "$w.t yview scroll \[expr \"int(\[$w.t cget -height\]/2)\"\] u"
    bind $w D "$w.t yview scroll \[expr \"int(\[$w.t cget -height\]/2)\"\] u"
    bind $w u "$w.t yview scroll \[expr \"int(-\[$w.t cget -height\]/2)\"\] u"
    bind $w U "$w.t yview scroll \[expr \"int(-\[$w.t cget -height\]/2)\"\] u"
    bind $w q "destroy $w"
    bind $w Q "destroy $w"
    $w.t insert end {Dirdiff instructions.

Dirdiff compares all the files in up to five directories.  There is one \
column in the main window for each directory.

Each file is shown with a coloured square indicating its status.  Files \
are like leaves on a deciduous tree: the newest ones are green, and then \
they turn yellow, orange, and red as they get older.  Missing files are \
black, and directories are white.

Double-click a file to show differences between two versions.  By default, \
the first and last versions are compared, but this can be changed by the \
'Diff' menu in the main window.  

You can select several files to copy or to make a patch by shift-clicking.

In the diff window, check the boxes on the left margin for changes you \
want to preserve, and then choose 'Merge' to move those changes into one \
of the files.  Alternatively, choose 'Copy' in the main window to copy \
across the whole file, replacing any changes.

'Make patch' produces a file describing the changes between the files that \
can be applied by the patch tool.  You can edit the patch before saving, \
and may wish to add explanatory text, instructions, or patch(1) Prereq \
lines at the beginning.  To save the patch, enter a filename in the patch \
window relative to the current directory, and choose 'Save'.  This will \
also close the window.

If you are sending out patches, then the "from" directory should be the \
original version of the source.  Try to make sure that the two files have \
the same number of leading directories.  See the patch(1) man page for \
more information.
    }

    $w.t conf -state disabled
}

proc filediffs {} {
    global groups selitem fserial
    updatefileinfo .
    set groups(.) [set gr [diffages . 1]]
    set fserial(.) 1
    dispfilelines $gr
    clearsecsel
    selcurfile
}

proc diffsin {sd} {
    global groups stopped showsame alllines
    foreach f [addfiles $sd] {
	if {$stopped} return
	lappend alllines $f
	set d [string trimright $f /]
	if {$d == $f} {
	    set groups($f) [set gr [diffages $f $showsame]]
	    if [interesting_line $gr] {
		displine $gr $f
	    }
	} else {
	    set groups($f) [set gr [subdirgroups $d]]
	    if [interesting_line $gr] {
		displine $gr $f
	    }
	    diffsin $f
	}
	catch update
    }
}

proc canvdiffs {} {
    global canvw groups stopped filemode alllines
    global filetype filetime filesize
    set stopped 0
    set alllines {}
    catch {unset filetype}
    catch {unset filetime}
    catch {unset filesize}
    initcanv
    if {$filemode} {
	filediffs
    } else {
	diffsin {}
	if {[catch update]} return
	ruleoff $stopped
    }
    if {[catch update]} return
    if {[lindex [$canvw yview] 1] >= 1.0} {
	$canvw yview moveto 0
    }
}

proc textitemat {x y} {
    global canvw
    foreach i [$canvw find overlapping $x $y [expr $x+50] $y] {
	if {[$canvw type $i] == "text"} {
	    return $i
	}
    }
    return {}
}

proc selcanvline {x y tipe} {
    global canvw stringx selitem secsel clickitem groups selfile clickmode
    global filemode doubleclick
    if {$filemode} return
    set x [expr $stringx+5]
    set y [$canvw canvasy $y]
    set it [textitemat $x $y]
    if {$it == {}} return
    if {$tipe == 0} {
	# click, no shift
	clearsecsel
	set selitem $it
	$canvw select from $it 0
	$canvw select to $it end
	set clickitem $it
	set clickmode 1
	selcurfile
	addsecsel $it
	set doubleclick 0
    } elseif {$tipe == 1} {
	# shift-click
	set clickitem $it
	if {$it != $selitem} {
	    if {![info exists secsel($it)]} {
		set clickmode 1
		addsecsel $it
	    } else {
		set clickmode 0
		remsecsel $it
	    }
	}
	set doubleclick 0
    } elseif {$tipe == 2} {
	if {[info exists doubleclick] && $doubleclick} return
	if {![info exists clickitem]} return
	foreach i [eval $canvw find overlapping [$canvw bbox $clickitem $it]] {
	    if {[$canvw type $i] == "text"} {
		set f [$canvw itemcget $i -text]
		if {$groups($f) == $groups($selfile)} {
		    if {$clickmode && ![info exists secsel($i)]} {
			addsecsel $i
		    } elseif {!$clickmode && [info exists secsel($i)]} {
			remsecsel $i
		    }
		}
	    }
	}
    }
}

proc addsecsel {it} {
    global canvw secsel
    set t [eval $canvw create rect [$canvw bbox $it] -outline {{}} \
	    -tags secsel -fill [$canvw cget -selectbackground]]
    $canvw lower $t
    set secsel($it) $t
}

proc remsecsel {it} {
    global canvw secsel
    $canvw delete $secsel($it)
    unset secsel($it)
}

proc clearsecsel {} {
    global canvw secsel
    $canvw delete secsel
    catch {unset secsel}
}

proc selnextline {inc} {
    global canvw selitem linespc stringx canvy filemode
    if {$filemode} {
	if {$inc != 0} {
	    return 0
	}
	selcurfile
	return 1
    }
    if {$selitem == ""} {
	return 0
    }
    set y [expr [lindex [$canvw bbox $selitem] 1] + $linespc * $inc + 5]
    set x [expr $stringx+5]
    set i [textitemat $x $y]
    if {$i == ""} {
	return 0
    }
    clearsecsel
    set selitem $i
    $canvw select from $i 0
    $canvw select to $i end
    set bbox [$canvw bbox $i]
    set y [expr {([lindex $bbox 1] + [lindex $bbox 3]) / 2.0}]
    set ytop [expr {($y - $linespc / 2.0) / $canvy}]
    set ybot [expr {($y + $linespc / 2.0) / $canvy}]
    set wnow [$canvw yview]
    if {$ytop < [lindex $wnow 0]} {
	$canvw yview moveto $ytop
    } elseif {$ybot > [lindex $wnow 1]} {
	set wh [expr {[lindex $wnow 1] - [lindex $wnow 0]}]
	$canvw yview moveto [expr {$ybot - $wh}]
    }
    selcurfile
    addsecsel $i
    return 1
}

proc calcgroupelts {f} {
    global groupelts numgroups groups
    set gr $groups($f)
    set numgroups [lindex $gr 0]
    if {$numgroups == "dir"} {
	set numgroups 1
    }
    set gr [lindex $gr 1]
    for {set g 0} {$g <= $numgroups} {incr g} {
	set groupelts($g) {}
    }
    set i 0
    foreach g $gr {
	lappend groupelts($g) $i
	incr i
    }
}

proc selcurfile {} {
    global canvw selitem filelabel selfile groups filemode
    global groupelts diffbut copybut numgroups
    if {!$filemode} {
	if {$selitem == ""} return
	set selfile [$canvw itemcget $selitem -text]
    } else {
	set selfile .
    }
    calcgroupelts $selfile
    set x [string trimright $selfile /]
    if {$x == $selfile} {
	if {[info exists filelabel]} {
	    $filelabel conf -text "File: $selfile"
	}
	confdiffbut 0
	confcopybutfile
    } else {
	if {[info exists filelabel]} {
	    $filelabel conf -text "Directory: $x"
	}
	confdiffbut 1
	confcopybutdir
    }
}

proc confdiffbut {isdir} {
    global diffbut numgroups dirs selfile groupelts filemode
    $diffbut.m delete 0 end
    if {$isdir} {
	# do nothing
    } elseif {$numgroups == 1} {
	set xi [lindex $groupelts(1) 0]
	if {$xi != ""} {
	    set x [lindex $dirs $xi]
	    $diffbut.m add command -label "Show $x" \
		    -command "showfile $x $selfile"
	}
    } elseif {$numgroups > 1} {
	for {set gn 1} {$gn < $numgroups} {incr gn} {
	    set yi [lindex $groupelts($gn) 0]
	    if {$yi == ""} continue
	    set y [lindex $dirs $yi]
	    for {set go [expr $gn + 1]} {$go <= $numgroups} {incr go} {
		set xi [lindex $groupelts($go) 0]
		if {$xi == ""} continue
		set x [lindex $dirs $xi]
		$diffbut.m add command -label "$x vs. $y" \
			-command "diff2 $x $y $selfile"
	    }
	}
    }
    if {!$filemode} {
	$diffbut.m add separator
	$diffbut.m add command -label "Rediff selected file(s)" \
		-command "redifffiles"
    }
    $diffbut conf -state normal
}

proc confcopybutfile {} {
    global copybut groupelts numgroups selfile dirs
    $copybut.m delete 0 end
    set numdirs [llength $dirs]
    set srcs {}
    set rev {}
    for {set gn 1} {$gn <= $numgroups} {incr gn} {
	set srcs [concat $srcs $groupelts($gn)]
	set src [lindex $groupelts($gn) 0]
	if {$src == ""} continue
	set x [lindex $dirs $src]
	for {set dst 0} {$dst < $numdirs} {incr dst} {
	    if {[lsearch $srcs $dst] < 0} {
		set y [lindex $dirs $dst]
		$copybut.m add command -label "$x -> $y" \
			-command "copyselfile $src $dst $selfile 0"
	    }
	}
    }
    set needsep 1
    for {set gn $numgroups} {$gn >= 1} {incr gn -1} {
	set src [lindex $groupelts($gn) 0]
	if {$src == ""} continue
	set x [lindex $dirs $src]
	for {set gd 1} {$gd < $gn} {incr gd} {
	    foreach dst $groupelts($gd) {
		set y [lindex $dirs $dst]
		if $needsep {
		    $copybut.m add separator
		    set needsep 0
		}
		$copybut.m add command -label "$x -> $y" \
			-command "copyselfile $src $dst $selfile 1"
	    }
	}
    }
    if {$groupelts(0) != {}} {
	set needsep 1
	for {set gn 1} {$gn <= $numgroups} {incr gn} {
	    foreach dst $groupelts($gn) {
		set x [lindex $dirs $dst]
		if $needsep {
		    $copybut.m add separator
		    set needsep 0
		}
		$copybut.m add command -label "Remove from $x" \
			-command "removeselfile $dst $selfile"
	    }
	}
    }
    $copybut conf -state normal
}

proc confcopybutdir {} {
    global copybut groupelts selfile dirs
    $copybut.m delete 0 end
    set srcs $groupelts(1)
    set dsts $groupelts(0)
    if {$srcs != {} && $dsts != {}} {
	foreach s $srcs {
	    set x [lindex $dirs $s]
	    foreach d $dsts {
		set y [lindex $dirs $d]
		$copybut.m add command -label "$x -> $y" \
			-command "copyselfile $s $d $selfile 0"
	    }
	}
	$copybut.m add separator
	foreach s $srcs {
	    set x [lindex $dirs $s]
	    $copybut.m add command -label "Remove from $x" \
		    -command "removeselfile $s $selfile"
	}
    }
    $copybut conf -state normal
}

proc resetsel {} {
    global selitem selfile filelabel diffbut copybut
    global canvw
    set selitem {}
    set selfile {}
    $canvw select clear
    if {[info exists filelabel]} {
	$filelabel conf -text "File: "
    }
    $diffbut conf -state disabled
    $copybut conf -state disabled
    removediffs
}

proc removediffs {} {
    global texttop textw diffing difff
    catch {destroy $texttop}
    catch {unset texttop}
    catch {unset textw}
    catch {close $difff}
    set diffing 0
}

proc showfile {d f} {
    global textw difflist texttop mergebut
    if {!([info exists textw] && [winfo exists $textw])} {
	maketextw
    } else {
	raise $texttop
    }
    set fn [joinname $d $f]
    wm title $texttop "Contents of $fn"
    set difflist {}
    $mergebut.m delete 0 end
    $textw conf -state normal -tabs {}
    $textw delete 0.0 end
    set nl {}
    set f [open $fn r]
    set n [gets $f line]
    while {$n >= 0} {
	$textw insert end "$nl$line"
	set nl "\n"
	set n [gets $f line]
    }
    close $f
    $textw conf -state disabled
}

proc redifffiles {} {
    global groups showsame selfile rediffed
    set files [secondarysel $selfile]
    foreach f $files {
	updatefileinfo $f
	set d [string trimright $f /]
	if {$d == $f} {
	    set groups($f) [diffages $f 1]
	} else {
	    set groups($f) [subdirgroups $d]
	}
	refreshcline $f
    }
    selcurfile
    set rediffed $selfile
}

proc diff2 {d1 d2 f} {
    global textw groups dirs numgroups bgcolors selfile difflist texttop
    global difff lno diffdirs diffiflag diffwflag diffbflag diffBflag diffdflag
    global ctxlines diffoldcolor diffnewcolor difffile charwidth mergebut
    global diffing filemode rediffed diffnewfirst
    set group [lindex $groups($selfile) 1]
    set i1 [lindex $group [lsearch $dirs $d1]]
    set i2 [lindex $group [lsearch $dirs $d2]]
    if {($i1 > $i2) == $diffnewfirst} {
	set x $d1
	set d1 $d2
	set d2 $x
	set x $i1
	set i1 $i2
	set i2 $x
    }
    set ds [list $d1 $d2]
    if {$diffing} {
	if {$ds == $diffdirs && $f == $difffile} return
	catch {close $difff}
    }
    set diffdirs $ds
    set difffile $f
    if {[info exists rediffed] && $rediffed == $f} {
	unset rediffed
    }
    if {![info exists textw] || ![winfo exists $textw]} {
	maketextw
    }
    if {$filemode} {
	wm title $texttop "Differences: $d1 vs $d2"
    } else {
	wm title $texttop "Differences: $f"
    }
    set difflist {}
    $mergebut.m delete 0 end
    $textw conf -state normal
    $textw delete 0.0 end
    set charwidth [font measure [$textw cget -font] n]
    $textw conf -tabs "[expr 4*$charwidth]p left [expr 12*$charwidth]p left"
    set x $bgcolors($numgroups)
    $textw tag delete [$textw tag names]
    set diffoldcolor [lindex $x $i1]
    set diffnewcolor [lindex $x $i2]
    $textw tag conf d1 -back $diffoldcolor
    $textw tag conf d2 -back $diffnewcolor
    $textw tag conf sep -back blue
    $textw tag conf ul -underline 1
    $textw tag lower sep
    set path1 [joinname $d1 $f]
    set path2 [joinname $d2 $f]
    set diffopts "-U $ctxlines $diffiflag $diffwflag $diffbflag $diffBflag $diffdflag"
    set difff [open "|diff $diffopts $path1 $path2" r]
    set diffing 1
    set lno 1
    catch {unset oldin}
    catch {unset newin}
    global linegroups linegroupnum linegrouplast lineinfo
    catch {unset linegroups}
    set linegroupnum 0
    set linegrouplast 0
    catch {unset lineinfo}
    global file1lnum file2lnum incline lineinfo
    set file1lnum 0
    set file2lnum 0
    catch {unset incline}
    catch {unset lineinfo}
    fconfigure $difff -blocking 0
    fileevent $difff readable "readdiff $difff"
}

proc readdiff {f} {
    global difff lno textw difflist
    global incline lineinfo underlinetabs
    global linegroups linegroupnum linegrouplast
    global file1lnum file2lnum diffing
    if {$f != $difff} {
	catch {close $f}
	return
    }
    set n [gets $difff line]
    if {$n < 0} {
	if {![eof $difff]} return
	catch {close $difff}
	set diffing 0
	if {$lno > 1} {
	    $textw delete "end - 1c" end
	    set t [$textw tag names "end - 1l"]
	    if {$t != ""} {
		$textw tag add $t "end - 1l" end
	    }
	}
	$textw conf -state disabled
	if {$lno > 3} {
	    global mergebut diffdirs difffile
	    global groups dirs diffmtime
	    set j 0
	    set group [lindex $groups($difffile) 1]
	    foreach i {0 1} {
		set g [lindex $group [lsearch $dirs [lindex $diffdirs $i]]]
		set k 0
		foreach gx $group {
		    if {$gx == $g} {
			set f [lindex $dirs $k]
			$mergebut.m add command -label "update $f" \
				-command [list diffmerge $i $j $f]
			set path [joinname $f $difffile]
			set diffmtime($path) [file mtime $path]
			incr j
		    }
		    incr k
		}
	    }
	}
	return
    }
    set x [string index $line 0]
    if {$x == "@" && [regexp { -([0-9,]+) .*\+([0-9,]+) } $line z r1 r2]} {
	set line "\t            $r1        $r2       "
	set file1lnum [string range $r1 0 [expr [string wordend $r1 0]-1]]
	set file2lnum [string range $r2 0 [expr [string wordend $r2 0]-1]]
	lappend difflist $lno
	set line [string range $line 1 end]
	$textw insert end "$line\n"
	set lend [$textw index "$lno.0 + 1l"]
	set i1 [$textw index "$lno.16 + [string length $r1] c"]
	set i2 [$textw index "$i1 + 8c + [string length $r2] c"]
	$textw tag add sep $lno.0 $lno.8
	$textw tag add d1 $lno.8 $i1
	$textw tag add d2 $i1 $i2
	$textw tag add sep $i2 $lend
	set linegrouplast 0
	incr lno
	return
    }
    set ix 1
    if {($x == "-" || $x == "+") && $lno > 3} {
	set incline($lno) 0
	if {!$linegrouplast} {
	    incr linegroupnum
	    set linegroups($linegroupnum) {}
	    set linegrouplast 1
	}
	lappend linegroups($linegroupnum) $lno
	checkbutton $textw.inc$lno -variable incline($lno) \
		-font {Courier -10} -cursor top_left_arrow \
		-padx 2 -pady 0 -highlightthickness 0
	$textw window create end -window $textw.inc$lno
	bind $textw.inc$lno "<Shift-Button-1>" \
		"$textw.inc$lno toggle; togglegroup $linegroupnum $lno; break"
	bind $textw.inc$lno "<Any-Button-3>" \
		"$textw.inc$lno toggle; togglegroup $linegroupnum $lno"
	set ix 2
	set line [string range $line 1 end]
	set lineinfo($lno) [list $file1lnum $file2lnum [expr {$x=="+"}] $line]
    } elseif {$x == "-" || $x == "+"} {
	set line [string trimleft $line $x]
    } elseif {$x == " "} {
	set line [string range $line 1 end]
    }
    $textw insert end "\t"
    if {$underlinetabs} {
	set col 0
	set trailb [string length [string trimright $line]]
	while {[set tpos [string first "\t" $line]] >= 0} {
	    if {$tpos > 0} {
		$textw insert end [string range $line 0 [expr $tpos-1]]
		if {$trailb < $tpos} {
		    $textw tag add ul $lno.[expr $ix+$trailb] \
			    $lno.[expr $ix+$tpos]
		    set trailb 0
		} else {
		    set trailb [expr $trailb-$tpos]
		}
		incr ix $tpos
		incr col $tpos
	    }
	    set nsp [expr {8 - ($col & 7)}]
	    $textw insert end [string range "         " 1 $nsp] ul
	    set line [string range $line [expr $tpos+1] end]
	    incr ix $nsp
	    incr col $nsp
	    if {$trailb > 0} {incr trailb -1}
	}
	$textw insert end "$line\n"
	set tpos [string length $line]
	if {$trailb < $tpos} {
	    $textw tag add ul $lno.[expr $ix+$trailb] $lno.[expr $ix+$tpos]
	}
    } else {
	$textw insert end "$line\n"
    }
    set lend [$textw index "$lno.0 + 1l"]
    if {$x == "-"} {
	$textw tag add d1 $lno.0 $lend
    } elseif {$x == "+"} {
	$textw tag add d2 $lno.0 $lend
    } else {
	set linegrouplast 0
    }
    if {$linegrouplast} {
	$textw tag add bindtag$lno $lno.0 $lend
	$textw tag bind bindtag$lno "<Button-1>" \
		"$textw.inc$lno toggle; break"
	$textw tag bind bindtag$lno "<Shift-Button-1>" \
		"$textw.inc$lno toggle; togglegroup $linegroupnum $lno; break"
	$textw tag bind bindtag$lno "<Any-Button-3>" \
		"$textw.inc$lno toggle; togglegroup $linegroupnum $lno; break"
    }
    if {$x != "+"} {incr file1lnum}
    if {$x != "-"} {incr file2lnum}
    incr lno
}

proc togglegroup {group lno} {
    global incline linegroups textw
    if $incline($lno) {
	set state select
    } else {
	set state deselect
    }
    foreach l $linegroups($group) {
	$textw.inc$l $state
    }
}

proc invertbuttons {} {
    global incline textw
    foreach l [array names incline] {
	set incline($l) [expr {1 - $incline($l)}]
    }
}

proc mergelist {} {
    global incline lineinfo lno
    set mlist {}
    for {set i 1} {$i <= $lno} {incr i} {
	if {[info exists incline($i)]} {
	    lappend mlist [list $incline($i) $lineinfo($i)]
	}
    }
    return $mlist
}

proc diffmerge {ix j dir} {
    global diffdirs difffile diffmtime fserial
    global dirs diffoldcolor diffnewcolor
    set infile [joinname $dir $difffile]
    if {$diffmtime($infile) != [file mtime $infile]} {
	error_popup "File $infile has changed since the diff was performed."
	return
    }
    set mlist [mergelist]

    set di [lsearch -exact $dirs $dir]
    set fi $fserial($difffile)
    set w ".merge:$di:$fi"
    catch {destroy $w}
    toplevel $w
    wm title $w "Dirdiff: merged $infile"
    frame $w.bar -relief raised -border 2
    pack $w.bar -side top -fill x
    menubutton $w.bar.file -text File -menu $w.bar.file.m -padx 10 -pady 1
    menu $w.bar.file.m -tearoff 0
    $w.bar.file.m add command -label Save -command "savemerge $w"
    $w.bar.file.m add command -label Close -command "destroy $w"
    pack $w.bar.file -side left
    menubutton $w.bar.edit -text Edit -menu $w.bar.edit.m -padx 10 -pady 1
    menu $w.bar.edit.m -tearoff 0
    $w.bar.edit.m add command -label Cut -command "tk_textCut $w.t"
    $w.bar.edit.m add command -label Copy -command "tk_textCopy $w.t"
    $w.bar.edit.m add command -label Paste -command "tk_textPaste $w.t"
    $w.bar.edit.m add command -label Find \
	    -command "difffind :merge:$di:$fi $w.t"
    pack $w.bar.edit -side left
    frame $w.f -relief sunk -border 2
    entry $w.f.filename
    $w.f.filename insert 0 $infile
    pack $w.f.filename -side left -fill x -expand 1
    pack $w.f -side top -fill x
    text $w.t -yscrollcommand "$w.sb set"
    scrollbar $w.sb -command "$w.t yview"
    pack $w.sb -side right -fill y
    pack $w.t -side left -fill both -expand 1
    bind $w <Key-Prior> "$w.t yview scroll -1 p"
    bind $w <Key-Next> "$w.t yview scroll 1 p"
    set cols [list $diffoldcolor $diffnewcolor]
    $w.t tag conf insl -back [lindex $cols [expr {1 - $ix}]]
    $w.t tag conf ndel -back [lindex $cols $ix]

    set inf [open $infile r]
    set l 1
    foreach mm $mlist {
	set inc [lindex $mm 0]
	set m [lindex $mm 1]
	set tl [lindex $m $ix]
	if {!$inc} {
	    if {[lindex $m 2] == $ix} {
		while {$l < $tl} {
		    if {[gets $inf line] < 0} return
		    $w.t insert end $line
		    $w.t insert end \n
		    incr l
		}
		if {[gets $inf line] < 0} return
		$w.t insert end $line ndel
		$w.t insert end \n ndel
		incr l
	    }
	    continue
	}
	while {$l < $tl} {
	    if {[gets $inf line] < 0} return
	    $w.t insert end $line
	    $w.t insert end \n
	    incr l
	}
	if {[lindex $m 2] != $ix} {
	    # insert this line
	    $w.t insert end [lindex $m 3] insl
	    $w.t insert end \n insl
	} else {
	    # delete this line
	    if {[gets $inf line] < 0} return
	    incr l
	}
    }
    while {[gets $inf line] >= 0} {
	$w.t insert end $line
	$w.t insert end \n
    }
    # delete last newline
    catch {$w.t delete "end - 1c" end}
    close $inf
}

proc savemerge {w} {
    set infile [$w.f.filename get]
    if {$infile == {}} {return}
    set tmpfile "$infile.tmp"
    set tf [open $tmpfile w]
    puts -nonewline $tf [$w.t get 0.0 end]
    close $tf
    bkedit $infile
    catch {file attr $tmpfile -perm [file attr $infile -perm]}
    file rename -force $infile $infile.orig
    file rename $tmpfile $infile
    destroy $w
    redifffiles
}

proc nextdiff {} {
    global textw difflist
    set ltop [expr int([$textw index @0,0])]
    foreach l $difflist {
	if {$l > $ltop} {
	    $textw yview $l.0
	    break
	}
    }
}

proc prevdiff {} {
    global textw difflist
    set ltop [expr int([$textw index @0,0])]
    set lprev {}
    foreach l $difflist {
	if {$l >= $ltop} {
	    if {$lprev != {}} {
		$textw yview $lprev.0
	    }
	    break
	}
	set lprev $l
    }
}

proc diffnextfile {inc} {
    global diffdirs selfile numgroups groups dirs textw
    global canvy ycoord canvw
    if {!([info exists textw] && [winfo exists $textw])} return
    if {![selnextline $inc] || $numgroups <= 1 || ![info exists diffdirs]} {
	return
    }
    set d1 [lindex $diffdirs 0]
    set d2 [lindex $diffdirs 1]
    set group [lindex $groups($selfile) 1]
    set i1 [lindex $group [lsearch $dirs $d1]]
    set i2 [lindex $group [lsearch $dirs $d2]]
    if {$i1 == 0 || $i2 == 0 || $i1 == $i2} return
    diff2 $d1 $d2 $selfile
}

proc showsomediff {inc} {
    global diffdirs difffile selfile numgroups groups dirs textw
    global canvy ycoord canvw groupelts dirinterest
    if {![selnextline $inc]} return
    if {[lindex $groups($selfile) 0] == "dir"} return

    if {$numgroups <= 1} {
	set xi [lindex $groupelts(1) 0]
	if {$xi != ""} {
	    showfile [lindex $dirs $xi] $selfile
	}
	return
    }

    set group [lindex $groups($selfile) 1]

    set g1 1
    set g2 1
    if {[info exists diffdirs] && [info exists difffile]} {
	set d1 [lindex $diffdirs 0]
	set d2 [lindex $diffdirs 1]
	set i1 [lsearch $dirs $d1]
	set i2 [lsearch $dirs $d2]
	set g1 [lindex $group $i1]
	set g2 [lindex $group $i2]
	if {$difffile != $selfile || \
		([info exists rediffed] && $rediffed == $difffile)} {
	    # looking at a different file from last time,
	    # try to do the same diff
	    if {$g1 > 0 && $g2 > 0 && $g1 != $g2 \
		    && $dirinterest($i1) && $dirinterest($i2)} {
		diff2 $d1 $d2 $selfile
		return
	    }
	    set g1 1
	    set g2 1
	} else {
	    # looking at the same file as last time,
	    # do the next diff
	    if {$g2 < $g1} {
		set x $g1
		set g1 $g2
		set g2 $x
	    }
	}
    }

    # work out which groups are interesting (have interesting dirs)
    for {set g 0} {$g <= $numgroups} {incr g} {
	set groupinterest($g) {}
	foreach i $groupelts($g) {
	    if $dirinterest($i) {
		set groupinterest($g) $i
		break
	    }
	}
    }

    set ncomb [expr {$numgroups * ($numgroups - 1) / 2}]
    for {} {$ncomb > 0} {incr ncomb -1} {
	if {[incr g2] > $numgroups} {
	    if {[incr g1] >= $numgroups} {
		set g1 1
	    }
	    set g2 [expr {$g1 + 1}]
	}
	if {$groupelts($g1) != {} && $groupelts($g2) != {} \
		&& $groupinterest($g1) != {} && $groupinterest($g2) != {}} {
	    set d1 [lindex $dirs $groupinterest($g1)]
	    set d2 [lindex $dirs $groupinterest($g2)]
	    diff2 $d1 $d2 $selfile
	    return
	}
    }
}

proc copydifffile {} {
    global diffdirs selfile groups dirs
    if {![info exists diffdirs]} return
    set d1 [lindex $diffdirs 0]
    set d2 [lindex $diffdirs 1]
    if {[lindex $groups($selfile) 0] == "dir"} return
    set group [lindex $groups($selfile) 1]
    set n1 [lsearch $dirs $d1]
    set n2 [lsearch $dirs $d2]
    set i1 [lindex $group $n1]
    set i2 [lindex $group $n2]
    if {$i1 == 0 || $i2 == 0 || $i1 == $i2} return
    copyfile $n2 $n1 $selfile 0
}

proc maketextw {} {
    global textw texttop mergebut filemode
    toplevel .diffs
    wm title .diffs "Differences"
    frame .diffs.bar -relief sunken -border 2
    pack .diffs.bar -side top -fill x
    button .diffs.bar.rediff -text Rediff -command "diffnextfile 0"
    pack .diffs.bar.rediff -side left
    button .diffs.bar.options -text Options -command diffoptions
    pack .diffs.bar.options -side left
    button .diffs.bar.find -text Find -command "difffind :diffs .diffs.t"
    pack .diffs.bar.find -side left
    menubutton .diffs.bar.merge -text Merge -menu .diffs.bar.merge.m -padx 10
    menu .diffs.bar.merge.m -tearoff 0
    pack .diffs.bar.merge -side left
    if {!$filemode} {
	button .diffs.bar.next -text "Next file" -command "diffnextfile 1"
	pack .diffs.bar.next -side left
	button .diffs.bar.prev -text "Previous file" -command "diffnextfile -1"
	pack .diffs.bar.prev -side left
    }
    button .diffs.bar.invert -text "Invert" -command "invertbuttons"
    pack .diffs.bar.invert -side left
    set texttop .diffs
    set textw .diffs.t
    set mergebut .diffs.bar.merge
    text $textw -width 84 -height 32 -yscrollcommand ".diffs.sb set"
    scrollbar .diffs.sb -command "$textw yview"
    pack .diffs.sb -side right -fill y
    pack $textw -side left -fill both -expand 1
    bind .diffs <Key-Prior> "$textw yview scroll -1 p"
    bind .diffs b "$textw yview scroll -1 p"
    bind .diffs B "$textw yview scroll -1 p"
    bind .diffs <Key-BackSpace> "$textw yview scroll -1 p"
    bind .diffs <Key-Delete> "$textw yview scroll -1 p"
    bind .diffs <Key-Next> "$textw yview scroll 1 p"
    bind .diffs <Key-space> "$textw yview scroll 1 p"
    bind .diffs <Key-Up> "$textw yview scroll -1 u"
    bind .diffs <Key-Down> "$textw yview scroll 1 u"
    bind .diffs d "$textw yview scroll \[expr \"int(\[$textw cget -height\]/2)\"\] u"
    bind .diffs D "$textw yview scroll \[expr \"int(\[$textw cget -height\]/2)\"\] u"
    bind .diffs u "$textw yview scroll \[expr \"int(-\[$textw cget -height\]/2)\"\] u"
    bind .diffs U "$textw yview scroll \[expr \"int(-\[$textw cget -height\]/2)\"\] u"
    bind .diffs n nextdiff
    bind .diffs p prevdiff
    if {!$filemode} {
	bind .diffs N "diffnextfile 1"
	bind .diffs P "diffnextfile -1"
    }
    bind .diffs q removediffs
    bind .diffs Q "set stopped 1; destroy ."
    bind .diffs <Key-Home> "$textw yview 1.0"
    bind .diffs g "$textw yview 1.0"
    bind .diffs <Key-End> "$textw yview -pickplace \[$textw index end\]"
    bind .diffs G "$textw yview -pickplace \[$textw index end\]"
    bind .diffs C copydifffile
}

proc diffoptions {} {
    global optionw
    if {[info exists optionw] && [winfo exists $optionw]} {
	raise $optionw
	return
    }
    set optionw .options
    toplevel $optionw
    wm title .options "Dirdiff options"
    checkbutton $optionw.diffiflag -text "Ignore case" \
	    -offvalue "" -onvalue "-i" -anchor w
    pack $optionw.diffiflag -side top -fill x
    checkbutton $optionw.diffwflag -text "Ignore all white space" \
	    -offvalue "" -onvalue "-w" -anchor w
    pack $optionw.diffwflag -side top -fill x
    checkbutton $optionw.diffbflag -text "Ignore amount of white space" \
	    -offvalue "" -onvalue "-b" -anchor w
    pack $optionw.diffbflag -side top -fill x
    checkbutton $optionw.diffBflag -text "Ignore blank lines" \
	    -offvalue "" -onvalue "-B" -anchor w
    pack $optionw.diffBflag -side top -fill x
    checkbutton $optionw.diffdflag -text "Minimize diffs" \
	    -offvalue "" -onvalue "-d" -anchor w
    pack $optionw.diffdflag -side top -fill x
    checkbutton $optionw.ultabs -text "Underline tabs" -anchor w \
	    -variable underlinetabs
    pack $optionw.ultabs -side top -fill x
    checkbutton $optionw.newfirst -text "Newer file first" -anchor w \
	    -variable diffnewfirst
    pack $optionw.newfirst -side top -fill x
    frame $optionw.ctx
    pack $optionw.ctx -side top
    label $optionw.ctx.l -text "Lines of context: "
    pack $optionw.ctx.l -side left
    entry $optionw.ctx.v -width 5 -textvariable ctxlines
    pack $optionw.ctx.v -side left
    button $optionw.save -text "Save options" -command saveoptions
    pack $optionw.save -side top -fill x
    frame $optionw.space -height 6
    pack $optionw.space -side top -fill x
    button $optionw.dismiss -text "Dismiss" -command "destroy $optionw"
    pack $optionw.dismiss -side bottom -fill x
    bind $optionw <Return> "destroy $optionw"
}

proc saveoptions {} {
    global rcsflag diffiflag diffwflag diffbflag diffBflag diffdflag
    global ctxlines showsame underlinetabs bitkeeper nukefiles redisp_immed
    global bkgetmode diffnewfirst
    set f [open "~/.dirdiff" w]
    puts $f [list set rcsflag $rcsflag]
    puts $f [list set diffiflag $diffiflag]
    puts $f [list set diffwflag $diffwflag]
    puts $f [list set diffbflag $diffbflag]
    puts $f [list set diffBflag $diffBflag]
    puts $f [list set diffdflag $diffdflag]
    puts $f [list set ctxlines $ctxlines]
    puts $f [list set showsame $showsame]
    puts $f [list set underlinetabs $underlinetabs]
    puts $f [list set bitkeeper $bitkeeper]
    puts $f [list set bkgetmode $bkgetmode]
    puts $f [list set redisp_immed $redisp_immed]
    puts $f [list set diffnewfirst $diffnewfirst]
    puts $f [list set nukefiles $nukefiles]
    close $f
}

proc difffind {tag txt} {
    global dfindw$tag igncase$tag diffiflag regexp$tag backwards$tag
    if {[info exists dfindw$tag] && [winfo exists [set dfindw$tag]]} {
	raise [set dfindw$tag]
	return
    }
    set w .find$tag
    set dfindw$tag $w
    toplevel $w
    wm title $w "Dirdiff: Find"
    frame $w.f
    pack $w.f -side top -fill x -expand 1
    button $w.f.b -text "Find:" -command [list dofind $tag $txt $w]
    bind $w <Return> [list dofind $tag $txt $w]
    pack $w.f.b -side left
    entry $w.f.e
    pack $w.f.e -side right
    if {![info exists igncase$tag]} {
	set igncase$tag [expr {$diffiflag != {}}]
    }
    checkbutton $w.case -variable igncase$tag -text "Ignore case" -anchor w
    pack $w.case -side top -fill x
    checkbutton $w.regexp -variable regexp$tag -text "Regular expression" \
	    -anchor w
    pack $w.regexp -side top -fill x
    checkbutton $w.backwards -variable backwards$tag \
	    -text "Search backwards" -anchor w
    pack $w.backwards -side top -fill x
    button $w.close -text "Close" -command "destroy $w"
    pack $w.close -side top -fill x
}

proc dofind {tag txt w} {
    global dfindw$tag igncase$tag regexp$tag backwards$tag
    if {![winfo exists $txt]} return
    set w [set dfindw$tag]
    set str [$w.f.e get]
    if {$str == {}} return
    set back [set backwards$tag]
    # By default, start the search from the insertion point.
    # If there is a selection, start from the end of the selection for
    # a forwards search, or from the beginning for a backwards search.
    set start [$txt index insert]
    if {[$txt tag ranges sel] != {}} {
	if {$back} {
	    set start [$txt index sel.first]
	} else {
	    set start [$txt index sel.last]
	}
    }
    set opts {}
    if {$back} {
	lappend opts "-backwards"
    }
    if {[set regexp$tag]} {
	lappend opts "-regexp"
    }
    if {[set igncase$tag]} {
	lappend opts "-nocase"
    }
    set pos [eval $txt search $opts -count count -- [list $str] $start]
    if {$pos == {}} {
	bell
	return
    }
    set epos "$pos + $count c"
    $txt mark set insert $epos
    $txt tag remove sel 0.0 end
    $txt tag add sel $pos $epos
    $txt see $epos
    $txt see $pos
}

proc makepatch {d1 d2} {
    global patchnum selfile patchfiles
    set files [secondarysel $selfile]
    if {$files == {}} {
	error_popup "No files selected!"
	return
    }
    if {![info exists patchnum]} {
	set patchnum 0
    }
    set patchfiles($patchnum) $files
    set w ".patch:$patchnum"
    catch {destroy $w}
    toplevel $w
    wm title $w "Patch: $d1 to $d2"
    frame $w.bar -relief raised -border 2
    pack $w.bar -side top -fill x
    menubutton $w.bar.file -text File -menu $w.bar.file.m -padx 10 -pady 1
    menu $w.bar.file.m -tearoff 0
    $w.bar.file.m add command -label Save -command "savepatch $w"
    $w.bar.file.m add command -label Close -command "destroy $w"
    pack $w.bar.file -side left
    menubutton $w.bar.edit -text Edit -menu $w.bar.edit.m -padx 10 -pady 1
    menu $w.bar.edit.m -tearoff 0
    $w.bar.edit.m add command -label Cut -command "tk_textCut $w.t"
    $w.bar.edit.m add command -label Copy -command "tk_textCopy $w.t"
    $w.bar.edit.m add command -label Paste -command "tk_textPaste $w.t"
    $w.bar.edit.m add command -label Find \
	    -command "difffind :patch:$patchnum $w.t"
    pack $w.bar.edit -side left
    frame $w.f -relief sunk -border 2
    label $w.f.l -text "Filename: "
    entry $w.f.filename
    $w.f.filename insert 0 "patch$patchnum"
    pack $w.f.l -side left
    pack $w.f.filename -side left -fill x -expand 1
    pack $w.f -side top -fill x
    text $w.t -yscrollcommand "$w.sb set"
    scrollbar $w.sb -command "$w.t yview"
    pack $w.sb -side right -fill y
    pack $w.t -side left -fill both -expand 1
    bind $w <Key-Prior> "$w.t yview scroll -1 p"
    bind $w <Key-Next> "$w.t yview scroll 1 p"
    patchnext $patchnum $w $d1 $d2 0
    incr patchnum
}

proc patchnext {pnum w d1 d2 i} {
    global patchfiles
    update
    for {} {[set f [lindex $patchfiles($pnum) $i]] != {}} {incr i} {
	set p1 [joinname $d1 $f]
	set p2 [joinname $d2 $f]
	if {[file exists $p1]} {
	    if {[file exists $p2]} {
		set fh [open "|diff -u $p1 $p2" r]
		fconfigure $fh -blocking 0
		fileevent $fh readable "readpatch $fh $pnum $w $d1 $d2 $i $f"
		return
	    }
	    makenxpatch $w $p1 $p2 -
	} else {
	    if {[file exists $p2]} {
		makenxpatch $w $p1 $p2 +
	    }
	}
    }
    $w.t delete "end - 1c" end
    unset patchfiles($pnum)
}

proc makenxpatch {w p1 p2 c} {
    $w.t insert end "diff -urN $p1 $p2\n"
    set fmt "%a %b %d %H:%M:%S %Y"
    set d1 0
    if {$c == "-"} {
	set f [open $p1 r]
	set d1 [file mtime $p1]
    }
    $w.t insert end "--- $p1\t[clock format $d1 -format $fmt]\n"
    set d2 0
    if {$c == "+"} {
	set f [open $p2 r]
	set d2 [file mtime $p2]
    }
    $w.t insert end "+++ $p2\t[clock format $d2 -format $fmt]\n"
    set pos [$w.t index end-1c]
    set nl 0
    while {[gets $f line] >= 0} {
	incr nl
	$w.t insert end "$c$line\n"
    }
    catch {close $f}
    if {$c == "-"} {
	$w.t insert $pos "@@ -1,$nl +0,0 @@\n"
    } else {
	$w.t insert $pos "@@ -0,0 +1,$nl @@\n"
    }
}

proc readpatch {difff pnum w d1 d2 i f} {
    set n [gets $difff line]
    if {$n < 0} {
	if {![eof $difff]} return
	catch {close $difff}
	patchnext $pnum $w $d1 $d2 [expr $i+1]
	return
    }
    if {[string match "Binary*" $line]} return
    if {[string match "---*" $line]} {
	$w.t insert end "diff -urN [joinname $d1 $f] [joinname $d2 $f]\n"
    }
    $w.t insert end $line
    $w.t insert end "\n"
}

proc savepatch {w} {
    set outfile [$w.f.filename get]
    if {$outfile == {}} {return}
    set outf [open $outfile w]
    puts -nonewline $outf [$w.t get 0.0 end]
    close $outf
    destroy $w
}

# invoked from the File->Touch menu item
proc touchfiles {d} {
    global selfile
    set files [secondarysel $selfile]
    if {$files == {}} {
	error_popup "No files selected!"
	return
    }
    set now [clock seconds]
    set bad {}
    foreach f $files {
	set df [file join $d $f]
	if {[catch {file mtime $df $now} err]} {
	    append bad "$df: $err\n"
	}
    }
    if {$bad != {}} {
	error_popup "Errors occurred:\n$bad"
    }
    redifffiles
}

# invoked from the File->BK get menu item
proc bkgetfiles {d} {
    global selfile bkgetmode
    set files [secondarysel $selfile]
    if {$files == {}} {
	error_popup "No files selected!"
	return
    }
    set bad {}
    set flag "-qT"
    if {$bkgetmode != " "} {
	append flag $bkgetmode
    }
    foreach f $files {
	set df [file join $d $f]
	if {[catch {exec bk get $flag $df} err]} {
	    append bad "$df: $err\n"
	}
    }
    if {$bad != {}} {
	error_popup "Errors occurred:\n$bad"
    }
    redifffiles
}

proc exclfilelist {} {
    global exclw nukefiles
    if {[info exists exclw] && [winfo exists $exclw]} {
	raise $exclw
	return
    }
    toplevel .excl
    wm title .excl "Dirdiff: excluded files"
    set exclw .excl
    frame $exclw.b
    listbox $exclw.l -height 10 -width 40 -yscrollcommand "$exclw.sb set" \
	    -selectmode single
    scrollbar $exclw.sb -command "$exclw.l yview"
    entry $exclw.e
    pack $exclw.b -side bottom -fill x
    pack $exclw.e -side bottom -fill x
    pack $exclw.sb -side right -fill y
    pack $exclw.l -side left -fill both -expand 1
    button $exclw.b.add -text "Add" -padx 20 -command addexcl
    button $exclw.b.rem -text "Remove" -command remexcl
    button $exclw.b.close -text "Close" -command closeexcl
    pack $exclw.b.add -side left -fill x
    pack $exclw.b.rem -side left -fill x
    pack $exclw.b.close -side right -fill x
    bind $exclw.e <Return> "addexcl"
    foreach i $nukefiles {
	$exclw.l insert end $i
    }
}

proc addexcl {} {
    global exclw nukefiles
    if {[info exists exclw] && [winfo exists $exclw]} {
	set e [$exclw.e get]
	if {$e != {}} {
	    $exclw.l insert end $e
	    lappend nukefiles $e
	    $exclw.l see end
	}
    }
}

proc remexcl {} {
    global exclw nukefiles
    if {[info exists exclw] && [winfo exists $exclw]} {
	set s [$exclw.l curselection]
	if {$s != {}} {
	    $exclw.l delete $s
	    set nukefiles [lreplace $nukefiles $s $s]
	}
    }
}

proc closeexcl {} {
    global exclw
    catch {destroy $exclw}
    catch {unset exclw}
}

proc secondarysel {fname} {
    global secsel canvw
    set files {}
    foreach it [array names secsel] {
	lappend files [$canvw itemcget $it -text]
    }
    if {$files == {}} {
	if {$fname == {}} {
	    return {}
	}
	set files [list $fname]
    }
    return [lsort $files]
}

proc copyselfile {src dst fname confirm} {
    global dirs
    set files [secondarysel $fname]
    set n [llength $files]
    if {$n == 1} {
	copyfile $src $dst $fname $confirm
    } else {
	if {$confirm} {
	    set sd [lindex $dirs $src]
	    set dd [lindex $dirs $dst]
	    if {![confirm_popup "Copy $n older files from $sd to $dd?"]} {
		return
	    }
	}
	foreach f $files {
	    copyfile $src $dst $f 0
	}
    }
    selcurfile
}

proc copyfile {src dst fname confirm} {
    global dirs bitkeeper filemode
    set sd [lindex $dirs $src]
    set dd [lindex $dirs $dst]
    set srcf [joinname $sd $fname]
    set dstf [joinname $dd $fname]
    if {$filemode} {
	set msg "$src to $dst"
	set copydst $dstf
    } else {
	set msg "$fname from $sd to $dd"
	set copydst [file dirname $dstf]
    }
    if {$confirm} {
	if {![confirm_popup "Copy older $msg?"]} {
	    return
	}
    }
    set z [string trimright $fname /]
    if {$z != $fname} {
	copydir $src $dst $z
	return
    }
    bkedit $dstf
    if [catch {file copy -force -- $srcf $copydst} err] {
	error_popup "Error copying $msg: $err"
    } else {
	bknew $dstf
	updatecline $src $dst $fname
	if {$bitkeeper} {
	    # make file writable if it isn't already
	    set perm [file attr $dstf -perm]
	    if {($perm & 0200) == 0} {
		file attr $dstf -perm [expr {$perm | 0200}]
	    }
	}
    }
}

proc copydir {src dst dname} {
    global dirs groups alllines
    set sn [lindex $dirs $src]
    set dn [lindex $dirs $dst]
    if [catch {exec cp -p -r $sn/$dname [file dirname $dn/$dname]}] {
	error_popup "Error copying $dname from $sn to $dn: $err"
	return
    }
    foreach f $alllines {
	if [string match $dname* $f] {
	    updatecline $src $dst $f
	}
    }
}

proc bkedit {name} {
    global bitkeeper
    if {!$bitkeeper} return
    set sfile [file join [file dirname $name] SCCS "s.[file tail $name]"]
    if {[file isfile $sfile] && ![file writable $name]} {
	if [catch {exec bk edit -q $name} err] {
	    error_popup "Warning: couldn't check out $name: $err"
	}
    }
}

proc bknew {name} {
    global bitkeeper bkgetmode
    if {!$bitkeeper} return
    set sdir [file join [file dirname $name] SCCS]
    set sfile [file join $sdir "s.[file tail $name]"]
    if {[file isdir $sdir] && ![file exists $sfile]} {
	if [catch {exec bk new -q $name} err] {
	    error_popup "Warning: couldn't create new BK file $name: $err"
	} else {
	    set flag "-qT"
	    if {$bkgetmode != " "} {
		append flag $bkgetmode
	    }
	    if [catch {exec bk get $flag $name} err ] {
		error_popup "Warning: couldn't check out new BK file $name: $err"
	    }
	}
    }
}

proc removeselfile {dst fname} {
    global groupelts dirs
    set files [secondarysel $fname]
    if {$files == {}} return
    set nf 0
    set nd 0
    foreach x $files {
	if {[string range $x end end] == "/"} {
	    incr nd
	} else {
	    incr nf
	}
    }
    set dd [lindex $dirs $dst]
    if {$nd + $nf == 1} {
	set x [string trimright [joinname $dd $fname] /]
	if {![confirm_popup "Remove $x?"]} {
	    return
	}
    } else {
	set stuff "Remove "
	if {$nd > 0} {
	    if {$nd == 1} {
		append stuff "1 directory "
	    } else {
		append stuff "$nd directories "
	    }
	    if {$nf > 0} {
		append stuff "and "
	    }
	}
	if {$nf == 1} {
	    append stuff "1 file "
	} elseif {$nf > 1} {
	    append stuff "$nf files "
	}
	append stuff "from $dd?"
	if {![confirm_popup $stuff]} {
	    return
	}
    }
    foreach f $files {
	set d [string trimright $f /]
	set dstf [joinname $dd $d]
	if {$d == $f} {
	    set bad [catch {file delete $dstf} err]
	} else {
	    set bad [catch {file delete -force $dstf} err]
	}
	if $bad {
	    error_popup "Error deleting $dstf: $err"
	} else {
	    updatecline [lindex $groupelts(0) 0] $dst $f
	}
    }
    selcurfile
}

proc confirm_popup msg {
    global confirm_ok
    set confirm_ok 0
    set w .confirm
    toplevel $w
    wm transient $w .
    message $w.m -text $msg -justify center -aspect 400
    pack $w.m -side top -fill x -padx 20 -pady 20
    button $w.ok -text OK -command "set confirm_ok 1; destroy $w"
    pack $w.ok -side left -fill x
    button $w.cancel -text Cancel -command "destroy $w"
    pack $w.cancel -side right -fill x
    bind $w <Visibility> "grab $w; focus $w"
    tkwait window $w
    return $confirm_ok
}

proc error_popup msg {
    set w .error
    toplevel $w
    wm transient $w .
    message $w.m -text $msg -justify center -aspect 400
    pack $w.m -side top -fill x -padx 20 -pady 20
    button $w.ok -text OK -command "destroy $w"
    pack $w.ok -side bottom -fill x
    bind $w <Visibility> "grab $w; focus $w"
    tkwait window $w
}

proc notalldirs {dirs} {
    set type ""
    foreach d $dirs {
	if {[catch {file lstat $d stat} err]} {
	    puts stderr $err
	    exit 1
	}
	if {$type == ""} {
	    set type $stat(type)
	} elseif {$type != $stat(type)} {
	    puts stderr "Error: $d is a $stat(type) but [lindex $dirs 0] is a $type"
	    exit 1
	}
    }
    return [expr {$type == "file"}]
}

proc go {} {
    global diffing filemode dirs nextserial
    if {[llength $dirs] == 0} {exit 0}
    set diffing 0
    set nextserial 0
    set filemode [notalldirs $dirs]
    makewins
    initcanv
    resetsel
    update
    canvdiffs
}

proc rediff {} {
    initcanv
    resetsel
    update
    canvdiffs
}

proc repackgroups {gr} {
    if {[lindex $gr 0] == "dir"} {
	return $gr
    }
    set glist [lindex $gr 1]
    set glsort [lsort $glist]
    set ng(0) 0
    set lg 0
    set gc 0
    foreach e $glsort {
	if {$e != $lg} {
	    set lg $e
	    incr gc
	    set ng($e) $gc
	}
    }
    if {$gc == [lindex $gr 0]} {
	return $gr
    }
    set newlist {}
    foreach e $glist {
	lappend newlist $ng($e)
    }
    return [list $gc $newlist]
}

proc interesting_line {gr} {
    global dirinterest dirs showsame
    if {$gr == {}} {
	return 0
    }
    if {$showsame} {
	return 1
    }
    set glist [lindex $gr 1]
    set i 0
    foreach e $glist {
	if $dirinterest($i) {
	    if {[info exists first]} {
		if {$e != $first} {
		    return 1
		}
	    } else {
		set first $e
	    }
	}
	incr i
    }
    return 0
}

proc redisplay {} {
    global canvw canvy canvy0 alllines groups ruletype
    $canvw delete all
    set canvy $canvy0
    $canvw conf -scrollregion "0 0 0 1"
    resetsel
    foreach f $alllines {
	set gr $groups($f)
	if {$gr != {}} {
	    set gr [repackgroups $gr]
	    set groups($f) $gr
	    if {[interesting_line $gr]} {
		displine $gr $f
	    }
	}
    }
    if [info exists ruletype] {
	ruleoff $ruletype
    }
}

proc maybe_redisplay {} {
    global redisp_immed
    if $redisp_immed redisplay
}

if [info exists doit] {go}
