git-fetch-pack: Implement client part of the multi_ack extension

[git.git] / gitk

diff --git a/gitk b/gitk
index edf94bf..f1ea4e1 100755 (executable)
--- a/gitk
+++ b/gitk
@@ -1,6 +1,6 @@
 #!/bin/sh
 # Tcl ignores the next line -*- tcl -*- \
 #!/bin/sh
 # Tcl ignores the next line -*- tcl -*- \

-exec wish "$0" -- "${1+$@}"
+exec wish "$0" -- "$@"

 
 # Copyright (C) 2005 Paul Mackerras.  All rights reserved.
 # This program is free software; it may be used, copied, modified
 
 # Copyright (C) 2005 Paul Mackerras.  All rights reserved.
 # This program is free software; it may be used, copied, modified


@@ -18,7 +18,7 @@ proc gitdir {} {
 
 proc getcommits {rargs} {
     global commits commfd phase canv mainfont env
 
 proc getcommits {rargs} {
     global commits commfd phase canv mainfont env

-    global startmsecs nextupdate
+    global startmsecs nextupdate ncmupdate

     global ctext maincursor textcursor leftover
 
     # check that we can find a .git directory somewhere...
     global ctext maincursor textcursor leftover
 
     # check that we can find a .git directory somewhere...


@@ -31,6 +31,7 @@ proc getcommits {rargs} {
     set phase getcommits
     set startmsecs [clock clicks -milliseconds]
     set nextupdate [expr $startmsecs + 100]
     set phase getcommits
     set startmsecs [clock clicks -milliseconds]
     set nextupdate [expr $startmsecs + 100]

+    set ncmupdate 1

     if [catch {
        set parse_args [concat --default HEAD $rargs]
        set parsed_args [split [eval exec git-rev-parse $parse_args] "\n"]
     if [catch {
        set parse_args [concat --default HEAD $rargs]
        set parsed_args [split [eval exec git-rev-parse $parse_args] "\n"]


@@ -42,14 +43,14 @@ proc getcommits {rargs} {
        set parsed_args $rargs
     }
     if [catch {
        set parsed_args $rargs
     }
     if [catch {

-       set commfd [open "|git-rev-list --header --topo-order $parsed_args" r]
+       set commfd [open "|git-rev-list --header --topo-order --parents $parsed_args" r]

     } err] {
        puts stderr "Error executing git-rev-list: $err"
        exit 1
     }
     set leftover {}
     fconfigure $commfd -blocking 0 -translation lf
     } err] {
        puts stderr "Error executing git-rev-list: $err"
        exit 1
     }
     set leftover {}
     fconfigure $commfd -blocking 0 -translation lf

-    fileevent $commfd readable "getcommitlines $commfd"
+    fileevent $commfd readable [list getcommitlines $commfd]

     $canv delete all
     $canv create text 3 3 -anchor nw -text "Reading commits..." \
        -font $mainfont -tags textitems
     $canv delete all
     $canv create text 3 3 -anchor nw -text "Reading commits..." \
        -font $mainfont -tags textitems


@@ -58,7 +59,7 @@ proc getcommits {rargs} {
 }
 
 proc getcommitlines {commfd}  {
 }
 
 proc getcommitlines {commfd}  {

-    global commits parents cdate children nchildren
+    global commits parents cdate children

     global commitlisted phase commitinfo nextupdate
     global stopped redisplaying leftover
 
     global commitlisted phase commitinfo nextupdate
     global stopped redisplaying leftover
 


@@ -95,7 +96,19 @@ to allow selection of commits to be displayed.)}
            set leftover {}
        }
        set start [expr {$i + 1}]
            set leftover {}
        }
        set start [expr {$i + 1}]

-       if {![regexp {^([0-9a-f]{40})\n} $cmit match id]} {
+       set j [string first "\n" $cmit]
+       set ok 0
+       if {$j >= 0} {
+           set ids [string range $cmit 0 [expr {$j - 1}]]
+           set ok 1
+           foreach id $ids {
+               if {![regexp {^[0-9a-f]{40}$} $id]} {
+                   set ok 0
+                   break
+               }
+           }
+       }
+       if {!$ok} {

            set shortcmit $cmit
            if {[string length $shortcmit] > 80} {
                set shortcmit "[string range $shortcmit 0 80]..."
            set shortcmit $cmit
            if {[string length $shortcmit] > 80} {
                set shortcmit "[string range $shortcmit 0 80]..."


@@ -103,13 +116,15 @@ to allow selection of commits to be displayed.)}
            error_popup "Can't parse git-rev-list output: {$shortcmit}"
            exit 1
        }
            error_popup "Can't parse git-rev-list output: {$shortcmit}"
            exit 1
        }

-       set cmit [string range $cmit 41 end]
+       set id [lindex $ids 0]
+       set olds [lrange $ids 1 end]
+       set cmit [string range $cmit [expr {$j + 1}] end]

        lappend commits $id
        set commitlisted($id) 1
        lappend commits $id
        set commitlisted($id) 1

-       parsecommit $id $cmit 1
+       parsecommit $id $cmit 1 [lrange $ids 1 end]

        drawcommit $id
        if {[clock clicks -milliseconds] >= $nextupdate} {
        drawcommit $id
        if {[clock clicks -milliseconds] >= $nextupdate} {

-           doupdate
+           doupdate 1

        }
        while {$redisplaying} {
            set redisplaying 0
        }
        while {$redisplaying} {
            set redisplaying 0


@@ -120,7 +135,7 @@ to allow selection of commits to be displayed.)}
                    drawcommit $id
                    if {$stopped} break
                    if {[clock clicks -milliseconds] >= $nextupdate} {
                    drawcommit $id
                    if {$stopped} break
                    if {[clock clicks -milliseconds] >= $nextupdate} {

-                       doupdate
+                       doupdate 1

                    }
                }
            }
                    }
                }
            }


@@ -128,21 +143,32 @@ to allow selection of commits to be displayed.)}
     }
 }
 
     }
 }
 

-proc doupdate {} {
-    global commfd nextupdate
+proc doupdate {reading} {
+    global commfd nextupdate numcommits ncmupdate

 
 

-    incr nextupdate 100
-    fileevent $commfd readable {}
+    if {$reading} {
+       fileevent $commfd readable {}
+    }

     update
     update

-    fileevent $commfd readable "getcommitlines $commfd"
+    set nextupdate [expr {[clock clicks -milliseconds] + 100}]
+    if {$numcommits < 100} {
+       set ncmupdate [expr {$numcommits + 1}]
+    } elseif {$numcommits < 10000} {
+       set ncmupdate [expr {$numcommits + 10}]
+    } else {
+       set ncmupdate [expr {$numcommits + 100}]
+    }
+    if {$reading} {
+       fileevent $commfd readable [list getcommitlines $commfd]
+    }

 }
 
 proc readcommit {id} {
     if [catch {set contents [exec git-cat-file commit $id]}] return
 }
 
 proc readcommit {id} {
     if [catch {set contents [exec git-cat-file commit $id]}] return

-    parsecommit $id $contents 0
+    parsecommit $id $contents 0 {}

 }
 
 }
 

-proc parsecommit {id contents listed} {
+proc parsecommit {id contents listed olds} {

     global commitinfo children nchildren parents nparents cdate ncleft
 
     set inhdr 1
     global commitinfo children nchildren parents nparents cdate ncleft
 
     set inhdr 1


@@ -157,30 +183,26 @@ proc parsecommit {id contents listed} {
        set nchildren($id) 0
        set ncleft($id) 0
     }
        set nchildren($id) 0
        set ncleft($id) 0
     }

-    set parents($id) {}
-    set nparents($id) 0
+    set parents($id) $olds
+    set nparents($id) [llength $olds]
+    foreach p $olds {
+       if {![info exists nchildren($p)]} {
+           set children($p) [list $id]
+           set nchildren($p) 1
+           set ncleft($p) 1
+       } elseif {[lsearch -exact $children($p) $id] < 0} {
+           lappend children($p) $id
+           incr nchildren($p)
+           incr ncleft($p)
+       }
+    }

     foreach line [split $contents "\n"] {
        if {$inhdr} {
            if {$line == {}} {
                set inhdr 0
            } else {
                set tag [lindex $line 0]
     foreach line [split $contents "\n"] {
        if {$inhdr} {
            if {$line == {}} {
                set inhdr 0
            } else {
                set tag [lindex $line 0]

-               if {$tag == "parent"} {
-                   set p [lindex $line 1]
-                   if {![info exists nchildren($p)]} {
-                       set children($p) {}
-                       set nchildren($p) 0
-                       set ncleft($p) 0
-                   }
-                   lappend parents($id) $p
-                   incr nparents($id)
-                   # sometimes we get a commit that lists a parent twice...
-                   if {$listed && [lsearch -exact $children($p) $id] < 0} {
-                       lappend children($p) $id
-                       incr nchildren($p)
-                       incr ncleft($p)
-                   }
-               } elseif {$tag == "author"} {
+               if {$tag == "author"} {

                    set x [expr {[llength $line] - 2}]
                    set audate [lindex $line $x]
                    set auname [lrange $line 1 [expr {$x - 1}]]
                    set x [expr {[llength $line] - 2}]
                    set audate [lindex $line $x]
                    set auname [lrange $line 1 [expr {$x - 1}]]


@@ -216,7 +238,8 @@ proc parsecommit {id contents listed} {
 }
 
 proc readrefs {} {
 }
 
 proc readrefs {} {

-    global tagids idtags headids idheads
+    global tagids idtags headids idheads tagcontents
+

     set tags [glob -nocomplain -types f [gitdir]/refs/tags/*]
     foreach f $tags {
        catch {
     set tags [glob -nocomplain -types f [gitdir]/refs/tags/*]
     foreach f $tags {
        catch {


@@ -226,7 +249,8 @@ proc readrefs {} {
                set direct [file tail $f]
                set tagids($direct) $id
                lappend idtags($id) $direct
                set direct [file tail $f]
                set tagids($direct) $id
                lappend idtags($id) $direct

-               set contents [split [exec git-cat-file tag $id] "\n"]
+               set tagblob [exec git-cat-file tag $id]
+               set contents [split $tagblob "\n"]

                set obj {}
                set type {}
                set tag {}
                set obj {}
                set type {}
                set tag {}


@@ -241,6 +265,7 @@ proc readrefs {} {
                if {$obj != {} && $type == "commit" && $tag != {}} {
                    set tagids($tag) $obj
                    lappend idtags($obj) $tag
                if {$obj != {} && $type == "commit" && $tag != {}} {
                    set tagids($tag) $obj
                    lappend idtags($obj) $tag

+                   set tagcontents($tag) $tagblob

                }
            }
            close $fd
                }
            }
            close $fd


@@ -259,6 +284,32 @@ proc readrefs {} {
            close $fd
        }
     }
            close $fd
        }
     }

+    readotherrefs refs {} {tags heads}
+}
+
+proc readotherrefs {base dname excl} {
+    global otherrefids idotherrefs
+
+    set git [gitdir]
+    set files [glob -nocomplain -types f [file join $git $base *]]
+    foreach f $files {
+       catch {
+           set fd [open $f r]
+           set line [read $fd 40]
+           if {[regexp {^[0-9a-f]{40}} $line id]} {
+               set name "$dname[file tail $f]"
+               set otherrefids($name) $id
+               lappend idotherrefs($id) $name
+           }
+           close $fd
+       }
+    }
+    set dirs [glob -nocomplain -types d [file join $git $base *]]
+    foreach d $dirs {
+       set dir [file tail $d]
+       if {[lsearch -exact $excl $dir] >= 0} continue
+       readotherrefs [file join $base $dir] "$dname$dir/" {}
+    }

 }
 
 proc error_popup msg {
 }
 
 proc error_popup msg {


@@ -283,6 +334,7 @@ proc makewindow {} {
     menu .bar
     .bar add cascade -label "File" -menu .bar.file
     menu .bar.file
     menu .bar
     .bar add cascade -label "File" -menu .bar.file
     menu .bar.file

+    .bar.file add command -label "Reread references" -command rereadrefs

     .bar.file add command -label "Quit" -command doquit
     menu .bar.help
     .bar add cascade -label "Help" -menu .bar.help
     .bar.file add command -label "Quit" -command doquit
     menu .bar.help
     .bar add cascade -label "Help" -menu .bar.help


@@ -387,7 +439,7 @@ proc makewindow {} {
     set ctext .ctop.cdet.left.ctext
     text $ctext -bg white -state disabled -font $textfont \
        -width $geometry(ctextw) -height $geometry(ctexth) \
     set ctext .ctop.cdet.left.ctext
     text $ctext -bg white -state disabled -font $textfont \
        -width $geometry(ctextw) -height $geometry(ctexth) \

-       -yscrollcommand ".ctop.cdet.left.sb set"
+       -yscrollcommand ".ctop.cdet.left.sb set" -wrap none

     scrollbar .ctop.cdet.left.sb -command "$ctext yview"
     pack .ctop.cdet.left.sb -side right -fill y
     pack $ctext -side left -fill both -expand 1
     scrollbar .ctop.cdet.left.sb -command "$ctext yview"
     pack .ctop.cdet.left.sb -side right -fill y
     pack $ctext -side left -fill both -expand 1


@@ -434,6 +486,8 @@ proc makewindow {} {
     bindall <B2-Motion> "allcanvs scan dragto 0 %y"
     bind . <Key-Up> "selnextline -1"
     bind . <Key-Down> "selnextline 1"
     bindall <B2-Motion> "allcanvs scan dragto 0 %y"
     bind . <Key-Up> "selnextline -1"
     bind . <Key-Down> "selnextline 1"

+    bind . <Key-Right> "goforw"
+    bind . <Key-Left> "goback"

     bind . <Key-Prior> "allcanvs yview scroll -1 pages"
     bind . <Key-Next> "allcanvs yview scroll 1 pages"
     bindkey <Key-Delete> "$ctext yview scroll -1 pages"
     bind . <Key-Prior> "allcanvs yview scroll -1 pages"
     bind . <Key-Next> "allcanvs yview scroll 1 pages"
     bindkey <Key-Delete> "$ctext yview scroll -1 pages"


@@ -441,6 +495,12 @@ proc makewindow {} {
     bindkey <Key-space> "$ctext yview scroll 1 pages"
     bindkey p "selnextline -1"
     bindkey n "selnextline 1"
     bindkey <Key-space> "$ctext yview scroll 1 pages"
     bindkey p "selnextline -1"
     bindkey n "selnextline 1"

+    bindkey z "goback"
+    bindkey x "goforw"
+    bindkey i "selnextline -1"
+    bindkey k "selnextline 1"
+    bindkey j "goback"
+    bindkey l "goforw"

     bindkey b "$ctext yview scroll -1 pages"
     bindkey d "$ctext yview scroll 18 units"
     bindkey u "$ctext yview scroll -18 units"
     bindkey b "$ctext yview scroll -1 pages"
     bindkey d "$ctext yview scroll 18 units"
     bindkey u "$ctext yview scroll -18 units"


@@ -506,6 +566,7 @@ proc click {w} {
 proc savestuff {w} {
     global canv canv2 canv3 ctext cflist mainfont textfont
     global stuffsaved findmergefiles gaudydiff maxgraphpct
 proc savestuff {w} {
     global canv canv2 canv3 ctext cflist mainfont textfont
     global stuffsaved findmergefiles gaudydiff maxgraphpct

+    global maxwidth

 
     if {$stuffsaved} return
     if {![winfo viewable .]} return
 
     if {$stuffsaved} return
     if {![winfo viewable .]} return


@@ -516,6 +577,7 @@ proc savestuff {w} {
        puts $f [list set findmergefiles $findmergefiles]
        puts $f [list set gaudydiff $gaudydiff]
        puts $f [list set maxgraphpct $maxgraphpct]
        puts $f [list set findmergefiles $findmergefiles]
        puts $f [list set gaudydiff $gaudydiff]
        puts $f [list set maxgraphpct $maxgraphpct]

+       puts $f [list set maxwidth $maxwidth]

        puts $f "set geometry(width) [winfo width .ctop]"
        puts $f "set geometry(height) [winfo height .ctop]"
        puts $f "set geometry(canv1) [expr [winfo width $canv]-2]"
        puts $f "set geometry(width) [winfo width .ctop]"
        puts $f "set geometry(height) [winfo height .ctop]"
        puts $f "set geometry(canv1) [expr [winfo width $canv]-2]"


@@ -692,21 +754,24 @@ proc assigncolor {id} {
 }
 
 proc initgraph {} {
 }
 
 proc initgraph {} {

-    global canvy canvy0 lineno numcommits lthickness nextcolor linespc
-    global mainline sidelines
+    global canvy canvy0 lineno numcommits nextcolor linespc
+    global mainline mainlinearrow sidelines

     global nchildren ncleft
     global nchildren ncleft

+    global displist nhyperspace

 
     allcanvs delete all
     set nextcolor 0
     set canvy $canvy0
     set lineno -1
     set numcommits 0
 
     allcanvs delete all
     set nextcolor 0
     set canvy $canvy0
     set lineno -1
     set numcommits 0

-    set lthickness [expr {int($linespc / 9) + 1}]

     catch {unset mainline}
     catch {unset mainline}

+    catch {unset mainlinearrow}

     catch {unset sidelines}
     foreach id [array names nchildren] {
        set ncleft($id) $nchildren($id)
     }
     catch {unset sidelines}
     foreach id [array names nchildren] {
        set ncleft($id) $nchildren($id)
     }

+    set displist {}
+    set nhyperspace 0

 }
 
 proc bindline {t id} {
 }
 
 proc bindline {t id} {


@@ -718,19 +783,47 @@ proc bindline {t id} {
     $canv bind $t <Button-1> "lineclick %x %y $id 1"
 }
 
     $canv bind $t <Button-1> "lineclick %x %y $id 1"
 }
 

+proc drawlines {id xtra} {
+    global mainline mainlinearrow sidelines lthickness colormap canv
+
+    $canv delete lines.$id
+    if {[info exists mainline($id)]} {
+       set t [$canv create line $mainline($id) \
+                  -width [expr {($xtra + 1) * $lthickness}] \
+                  -fill $colormap($id) -tags lines.$id \
+                  -arrow $mainlinearrow($id)]
+       $canv lower $t
+       bindline $t $id
+    }
+    if {[info exists sidelines($id)]} {
+       foreach ls $sidelines($id) {
+           set coords [lindex $ls 0]
+           set thick [lindex $ls 1]
+           set arrow [lindex $ls 2]
+           set t [$canv create line $coords -fill $colormap($id) \
+                      -width [expr {($thick + $xtra) * $lthickness}] \
+                      -arrow $arrow -tags lines.$id]
+           $canv lower $t
+           bindline $t $id
+       }
+    }
+}
+
+# level here is an index in displist

 proc drawcommitline {level} {
 proc drawcommitline {level} {

-    global parents children nparents nchildren todo
+    global parents children nparents displist

     global canv canv2 canv3 mainfont namefont canvy linespc
     global lineid linehtag linentag linedtag commitinfo
     global colormap numcommits currentparents dupparents
     global canv canv2 canv3 mainfont namefont canvy linespc
     global lineid linehtag linentag linedtag commitinfo
     global colormap numcommits currentparents dupparents

-    global oldlevel oldnlines oldtodo
-    global idtags idline idheads
-    global lineno lthickness mainline sidelines
-    global commitlisted rowtextx idpos
+    global idtags idline idheads idotherrefs
+    global lineno lthickness mainline mainlinearrow sidelines
+    global commitlisted rowtextx idpos lastuse displist
+    global oldnlines olddlevel olddisplist

 
     incr numcommits
     incr lineno
 
     incr numcommits
     incr lineno

-    set id [lindex $todo $level]
+    set id [lindex $displist $level]
+    set lastuse($id) $lineno

     set lineid($lineno) $id
     set idline($id) $lineno
     set ofill [expr {[info exists commitlisted($id)]? "blue": "white"}]
     set lineid($lineno) $id
     set idline($id) $lineno
     set ofill [expr {[info exists commitlisted($id)]? "blue": "white"}]


@@ -761,34 +854,25 @@ proc drawcommitline {level} {
        [list 0 0 0 [expr $y1 + 0.5 * $linespc + 2]]
     if {[info exists mainline($id)]} {
        lappend mainline($id) $x $y1
        [list 0 0 0 [expr $y1 + 0.5 * $linespc + 2]]
     if {[info exists mainline($id)]} {
        lappend mainline($id) $x $y1

-       set t [$canv create line $mainline($id) \
-                  -width $lthickness -fill $colormap($id)]
-       $canv lower $t
-       bindline $t $id
-    }
-    if {[info exists sidelines($id)]} {
-       foreach ls $sidelines($id) {
-           set coords [lindex $ls 0]
-           set thick [lindex $ls 1]
-           set t [$canv create line $coords -fill $colormap($id) \
-                      -width [expr {$thick * $lthickness}]]
-           $canv lower $t
-           bindline $t $id
+       if {$mainlinearrow($id) ne "none"} {
+           set mainline($id) [trimdiagstart $mainline($id)]

        }
     }
        }
     }

+    drawlines $id 0

     set orad [expr {$linespc / 3}]
     set t [$canv create oval [expr $x - $orad] [expr $y1 - $orad] \
               [expr $x + $orad - 1] [expr $y1 + $orad - 1] \
               -fill $ofill -outline black -width 1]
     $canv raise $t
     $canv bind $t <1> {selcanvline {} %x %y}
     set orad [expr {$linespc / 3}]
     set t [$canv create oval [expr $x - $orad] [expr $y1 - $orad] \
               [expr $x + $orad - 1] [expr $y1 + $orad - 1] \
               -fill $ofill -outline black -width 1]
     $canv raise $t
     $canv bind $t <1> {selcanvline {} %x %y}

-    set xt [xcoord [llength $todo] $level $lineno]
+    set xt [xcoord [llength $displist] $level $lineno]

     if {[llength $currentparents] > 2} {
        set xt [expr {$xt + ([llength $currentparents] - 2) * $linespc}]
     }
     set rowtextx($lineno) $xt
     set idpos($id) [list $x $xt $y1]
     if {[llength $currentparents] > 2} {
        set xt [expr {$xt + ([llength $currentparents] - 2) * $linespc}]
     }
     set rowtextx($lineno) $xt
     set idpos($id) [list $x $xt $y1]

-    if {[info exists idtags($id)] || [info exists idheads($id)]} {
+    if {[info exists idtags($id)] || [info exists idheads($id)]
+       || [info exists idotherrefs($id)]} {

        set xt [drawtags $id $x $xt $y1]
     }
     set headline [lindex $commitinfo($id) 0]
        set xt [drawtags $id $x $xt $y1]
     }
     set headline [lindex $commitinfo($id) 0]


@@ -801,21 +885,30 @@ proc drawcommitline {level} {
                               -text $name -font $namefont]
     set linedtag($lineno) [$canv3 create text 3 $y1 -anchor w \
                               -text $date -font $mainfont]
                               -text $name -font $namefont]
     set linedtag($lineno) [$canv3 create text 3 $y1 -anchor w \
                               -text $date -font $mainfont]

+
+    set olddlevel $level
+    set olddisplist $displist
+    set oldnlines [llength $displist]

 }
 
 proc drawtags {id x xt y1} {
 }
 
 proc drawtags {id x xt y1} {

-    global idtags idheads
+    global idtags idheads idotherrefs

     global linespc lthickness
     global linespc lthickness

-    global canv mainfont
+    global canv mainfont idline rowtextx

 
     set marks {}
     set ntags 0
 
     set marks {}
     set ntags 0

+    set nheads 0

     if {[info exists idtags($id)]} {
        set marks $idtags($id)
        set ntags [llength $marks]
     }
     if {[info exists idheads($id)]} {
        set marks [concat $marks $idheads($id)]
     if {[info exists idtags($id)]} {
        set marks $idtags($id)
        set ntags [llength $marks]
     }
     if {[info exists idheads($id)]} {
        set marks [concat $marks $idheads($id)]

+       set nheads [llength $idheads($id)]
+    }
+    if {[info exists idotherrefs($id)]} {
+       set marks [concat $marks $idotherrefs($id)]

     }
     if {$marks eq {}} {
        return $xt
     }
     if {$marks eq {}} {
        return $xt


@@ -840,61 +933,36 @@ proc drawtags {id x xt y1} {
        set xr [expr $x + $delta + $wid + $lthickness]
        if {[incr ntags -1] >= 0} {
            # draw a tag
        set xr [expr $x + $delta + $wid + $lthickness]
        if {[incr ntags -1] >= 0} {
            # draw a tag

-           $canv create polygon $x [expr $yt + $delta] $xl $yt\
-               $xr $yt $xr $yb $xl $yb $x [expr $yb - $delta] \
-               -width 1 -outline black -fill yellow -tags tag.$id
+           set t [$canv create polygon $x [expr $yt + $delta] $xl $yt \
+                      $xr $yt $xr $yb $xl $yb $x [expr $yb - $delta] \
+                      -width 1 -outline black -fill yellow -tags tag.$id]
+           $canv bind $t <1> [list showtag $tag 1]
+           set rowtextx($idline($id)) [expr {$xr + $linespc}]

        } else {
        } else {

-           # draw a head
+           # draw a head or other ref
+           if {[incr nheads -1] >= 0} {
+               set col green
+           } else {
+               set col "#ddddff"
+           }

            set xl [expr $xl - $delta/2]
            $canv create polygon $x $yt $xr $yt $xr $yb $x $yb \
            set xl [expr $xl - $delta/2]
            $canv create polygon $x $yt $xr $yt $xr $yb $x $yb \

-               -width 1 -outline black -fill green -tags tag.$id
-       }
-       $canv create text $xl $y1 -anchor w -text $tag \
-           -font $mainfont -tags tag.$id
-    }
-    return $xt
-}
-
-proc updatetodo {level noshortcut} {
-    global currentparents ncleft todo
-    global mainline oldlevel oldtodo oldnlines
-    global canvy linespc mainline
-    global commitinfo lineno xspc1
-
-    set oldlevel $level
-    set oldtodo $todo
-    set oldnlines [llength $todo]
-    if {!$noshortcut && [llength $currentparents] == 1} {
-       set p [lindex $currentparents 0]
-       if {$ncleft($p) == 1 && [lsearch -exact $todo $p] < 0} {
-           set ncleft($p) 0
-           set x [xcoord $level $level $lineno]
-           set y [expr $canvy - $linespc]
-           set mainline($p) [list $x $y]
-           set todo [lreplace $todo $level $level $p]
-           set xspc1([expr {$lineno + 1}]) $xspc1($lineno)
-           return 0
+               -width 1 -outline black -fill $col -tags tag.$id

        }
        }

-    }
-
-    set todo [lreplace $todo $level $level]
-    set i $level
-    foreach p $currentparents {
-       incr ncleft($p) -1
-       set k [lsearch -exact $todo $p]
-       if {$k < 0} {
-           set todo [linsert $todo $i $p]
-           incr i
+       set t [$canv create text $xl $y1 -anchor w -text $tag \
+                  -font $mainfont -tags tag.$id]
+       if {$ntags >= 0} {
+           $canv bind $t <1> [list showtag $tag 1]

        }
     }
        }
     }

-    return 1
+    return $xt

 }
 
 proc notecrossings {id lo hi corner} {
 }
 
 proc notecrossings {id lo hi corner} {

-    global oldtodo crossings cornercrossings
+    global olddisplist crossings cornercrossings

 
     for {set i $lo} {[incr i] < $hi} {} {
 
     for {set i $lo} {[incr i] < $hi} {} {

-       set p [lindex $oldtodo $i]
+       set p [lindex $olddisplist $i]

        if {$p == {}} continue
        if {$i == $corner} {
            if {![info exists cornercrossings($id)]
        if {$p == {}} continue
        if {$i == $corner} {
            if {![info exists cornercrossings($id)]


@@ -930,37 +998,219 @@ proc xcoord {i level ln} {
     return $x
 }
 
     return $x
 }
 

-proc drawslants {level} {
-    global canv mainline sidelines canvx0 canvy xspc1 xspc2 lthickness
-    global oldlevel oldtodo todo currentparents dupparents
+# it seems Tk can't draw arrows on the end of diagonal line segments...
+proc trimdiagend {line} {
+    while {[llength $line] > 4} {
+       set x1 [lindex $line end-3]
+       set y1 [lindex $line end-2]
+       set x2 [lindex $line end-1]
+       set y2 [lindex $line end]
+       if {($x1 == $x2) != ($y1 == $y2)} break
+       set line [lreplace $line end-1 end]
+    }
+    return $line
+}
+
+proc trimdiagstart {line} {
+    while {[llength $line] > 4} {
+       set x1 [lindex $line 0]
+       set y1 [lindex $line 1]
+       set x2 [lindex $line 2]
+       set y2 [lindex $line 3]
+       if {($x1 == $x2) != ($y1 == $y2)} break
+       set line [lreplace $line 0 1]
+    }
+    return $line
+}
+
+proc drawslants {id needonscreen nohs} {
+    global canv mainline mainlinearrow sidelines
+    global canvx0 canvy xspc1 xspc2 lthickness
+    global currentparents dupparents

     global lthickness linespc canvy colormap lineno geometry
     global lthickness linespc canvy colormap lineno geometry

-    global maxgraphpct
+    global maxgraphpct maxwidth
+    global displist onscreen lastuse
+    global parents commitlisted
+    global oldnlines olddlevel olddisplist
+    global nhyperspace numcommits nnewparents
+
+    if {$lineno < 0} {
+       lappend displist $id
+       set onscreen($id) 1
+       return 0
+    }
+
+    set y1 [expr {$canvy - $linespc}]
+    set y2 $canvy
+
+    # work out what we need to get back on screen
+    set reins {}
+    if {$onscreen($id) < 0} {
+       # next to do isn't displayed, better get it on screen...
+       lappend reins [list $id 0]
+    }
+    # make sure all the previous commits's parents are on the screen
+    foreach p $currentparents {
+       if {$onscreen($p) < 0} {
+           lappend reins [list $p 0]
+       }
+    }
+    # bring back anything requested by caller
+    if {$needonscreen ne {}} {
+       lappend reins $needonscreen
+    }
+
+    # try the shortcut
+    if {$currentparents == $id && $onscreen($id) == 0 && $reins eq {}} {
+       set dlevel $olddlevel
+       set x [xcoord $dlevel $dlevel $lineno]
+       set mainline($id) [list $x $y1]
+       set mainlinearrow($id) none
+       set lastuse($id) $lineno
+       set displist [lreplace $displist $dlevel $dlevel $id]
+       set onscreen($id) 1
+       set xspc1([expr {$lineno + 1}]) $xspc1($lineno)
+       return $dlevel
+    }
+
+    # update displist
+    set displist [lreplace $displist $olddlevel $olddlevel]
+    set j $olddlevel
+    foreach p $currentparents {
+       set lastuse($p) $lineno
+       if {$onscreen($p) == 0} {
+           set displist [linsert $displist $j $p]
+           set onscreen($p) 1
+           incr j
+       }
+    }
+    if {$onscreen($id) == 0} {
+       lappend displist $id
+       set onscreen($id) 1
+    }
+
+    # remove the null entry if present
+    set nullentry [lsearch -exact $displist {}]
+    if {$nullentry >= 0} {
+       set displist [lreplace $displist $nullentry $nullentry]
+    }
+
+    # bring back the ones we need now (if we did it earlier
+    # it would change displist and invalidate olddlevel)
+    foreach pi $reins {
+       # test again in case of duplicates in reins
+       set p [lindex $pi 0]
+       if {$onscreen($p) < 0} {
+           set onscreen($p) 1
+           set lastuse($p) $lineno
+           set displist [linsert $displist [lindex $pi 1] $p]
+           incr nhyperspace -1
+       }
+    }
+
+    set lastuse($id) $lineno
+
+    # see if we need to make any lines jump off into hyperspace
+    set displ [llength $displist]
+    if {$displ > $maxwidth} {
+       set ages {}
+       foreach x $displist {
+           lappend ages [list $lastuse($x) $x]
+       }
+       set ages [lsort -integer -index 0 $ages]
+       set k 0
+       while {$displ > $maxwidth} {
+           set use [lindex $ages $k 0]
+           set victim [lindex $ages $k 1]
+           if {$use >= $lineno - 5} break
+           incr k
+           if {[lsearch -exact $nohs $victim] >= 0} continue
+           set i [lsearch -exact $displist $victim]
+           set displist [lreplace $displist $i $i]
+           set onscreen($victim) -1
+           incr nhyperspace
+           incr displ -1
+           if {$i < $nullentry} {
+               incr nullentry -1
+           }
+           set x [lindex $mainline($victim) end-1]
+           lappend mainline($victim) $x $y1
+           set line [trimdiagend $mainline($victim)]
+           set arrow "last"
+           if {$mainlinearrow($victim) ne "none"} {
+               set line [trimdiagstart $line]
+               set arrow "both"
+           }
+           lappend sidelines($victim) [list $line 1 $arrow]
+           unset mainline($victim)
+       }
+    }
+
+    set dlevel [lsearch -exact $displist $id]
+
+    # If we are reducing, put in a null entry
+    if {$displ < $oldnlines} {
+       # does the next line look like a merge?
+       # i.e. does it have > 1 new parent?
+       if {$nnewparents($id) > 1} {
+           set i [expr {$dlevel + 1}]
+       } elseif {$nnewparents([lindex $olddisplist $olddlevel]) == 0} {
+           set i $olddlevel
+           if {$nullentry >= 0 && $nullentry < $i} {
+               incr i -1
+           }
+       } elseif {$nullentry >= 0} {
+           set i $nullentry
+           while {$i < $displ
+                  && [lindex $olddisplist $i] == [lindex $displist $i]} {
+               incr i
+           }
+       } else {
+           set i $olddlevel
+           if {$dlevel >= $i} {
+               incr i
+           }
+       }
+       if {$i < $displ} {
+           set displist [linsert $displist $i {}]
+           incr displ
+           if {$dlevel >= $i} {
+               incr dlevel
+           }
+       }
+    }

 
     # decide on the line spacing for the next line
     set lj [expr {$lineno + 1}]
     set maxw [expr {$maxgraphpct * $geometry(canv1) / 100}]
 
     # decide on the line spacing for the next line
     set lj [expr {$lineno + 1}]
     set maxw [expr {$maxgraphpct * $geometry(canv1) / 100}]

-    set n [llength $todo]
-    if {$n <= 1 || $canvx0 + $n * $xspc2 <= $maxw} {
+    if {$displ <= 1 || $canvx0 + $displ * $xspc2 <= $maxw} {

        set xspc1($lj) $xspc2
     } else {
        set xspc1($lj) $xspc2
     } else {

-       set xspc1($lj) [expr {($maxw - $canvx0 - $xspc2) / ($n - 1)}]
+       set xspc1($lj) [expr {($maxw - $canvx0 - $xspc2) / ($displ - 1)}]

        if {$xspc1($lj) < $lthickness} {
            set xspc1($lj) $lthickness
        }
     }
        if {$xspc1($lj) < $lthickness} {
            set xspc1($lj) $lthickness
        }
     }

-    
-    set y1 [expr $canvy - $linespc]
-    set y2 $canvy
+
+    foreach idi $reins {
+       set id [lindex $idi 0]
+       set j [lsearch -exact $displist $id]
+       set xj [xcoord $j $dlevel $lj]
+       set mainline($id) [list $xj $y2]
+       set mainlinearrow($id) first
+    }
+

     set i -1
     set i -1

-    foreach id $oldtodo {
+    foreach id $olddisplist {

        incr i
        if {$id == {}} continue
        incr i
        if {$id == {}} continue

-       set xi [xcoord $i $oldlevel $lineno]
-       if {$i == $oldlevel} {
+       if {$onscreen($id) <= 0} continue
+       set xi [xcoord $i $olddlevel $lineno]
+       if {$i == $olddlevel} {

            foreach p $currentparents {
            foreach p $currentparents {

-               set j [lsearch -exact $todo $p]
+               set j [lsearch -exact $displist $p]

                set coords [list $xi $y1]
                set coords [list $xi $y1]

-               set xj [xcoord $j $level $lj]
+               set xj [xcoord $j $dlevel $lj]

                if {$xj < $xi - $linespc} {
                    lappend coords [expr {$xj + $linespc}] $y1
                    notecrossings $p $j $i [expr {$j + 1}]
                if {$xj < $xi - $linespc} {
                    lappend coords [expr {$xj + $linespc}] $y1
                    notecrossings $p $j $i [expr {$j + 1}]


@@ -971,9 +1221,10 @@ proc drawslants {level} {
                if {[lsearch -exact $dupparents $p] >= 0} {
                    # draw a double-width line to indicate the doubled parent
                    lappend coords $xj $y2
                if {[lsearch -exact $dupparents $p] >= 0} {
                    # draw a double-width line to indicate the doubled parent
                    lappend coords $xj $y2

-                   lappend sidelines($p) [list $coords 2]
+                   lappend sidelines($p) [list $coords 2 none]

                    if {![info exists mainline($p)]} {
                        set mainline($p) [list $xj $y2]
                    if {![info exists mainline($p)]} {
                        set mainline($p) [list $xj $y2]

+                       set mainlinearrow($p) none

                    }
                } else {
                    # normal case, no parent duplicated
                    }
                } else {
                    # normal case, no parent duplicated


@@ -987,48 +1238,175 @@ proc drawslants {level} {
                            lappend coords $xj $yb
                        }
                        set mainline($p) $coords
                            lappend coords $xj $yb
                        }
                        set mainline($p) $coords

+                       set mainlinearrow($p) none

                    } else {
                        lappend coords $xj $yb
                        if {$yb < $y2} {
                            lappend coords $xj $y2
                        }
                    } else {
                        lappend coords $xj $yb
                        if {$yb < $y2} {
                            lappend coords $xj $y2
                        }

-                       lappend sidelines($p) [list $coords 1]
+                       lappend sidelines($p) [list $coords 1 none]

                    }
                }
            }
        } else {
            set j $i
                    }
                }
            }
        } else {
            set j $i

-           if {[lindex $todo $i] != $id} {
-               set j [lsearch -exact $todo $id]
+           if {[lindex $displist $i] != $id} {
+               set j [lsearch -exact $displist $id]

            }
            if {$j != $i || $xspc1($lineno) != $xspc1($lj)
            }
            if {$j != $i || $xspc1($lineno) != $xspc1($lj)

-               || ($oldlevel <= $i && $i <= $level)
-               || ($level <= $i && $i <= $oldlevel)} {
-               set xj [xcoord $j $level $lj]
-               set dx [expr {abs($xi - $xj)}]
-               set yb $y2
-               if {0 && $dx < $linespc} {
-                   set yb [expr {$y1 + $dx}]
+               || ($olddlevel < $i && $i < $dlevel)
+               || ($dlevel < $i && $i < $olddlevel)} {
+               set xj [xcoord $j $dlevel $lj]
+               lappend mainline($id) $xi $y1 $xj $y2
+           }
+       }
+    }
+    return $dlevel
+}
+
+# search for x in a list of lists
+proc llsearch {llist x} {
+    set i 0
+    foreach l $llist {
+       if {$l == $x || [lsearch -exact $l $x] >= 0} {
+           return $i
+       }
+       incr i
+    }
+    return -1
+}
+
+proc drawmore {reading} {
+    global displayorder numcommits ncmupdate nextupdate
+    global stopped nhyperspace parents commitlisted
+    global maxwidth onscreen displist currentparents olddlevel
+
+    set n [llength $displayorder]
+    while {$numcommits < $n} {
+       set id [lindex $displayorder $numcommits]
+       set ctxend [expr {$numcommits + 10}]
+       if {!$reading && $ctxend > $n} {
+           set ctxend $n
+       }
+       set dlist {}
+       if {$numcommits > 0} {
+           set dlist [lreplace $displist $olddlevel $olddlevel]
+           set i $olddlevel
+           foreach p $currentparents {
+               if {$onscreen($p) == 0} {
+                   set dlist [linsert $dlist $i $p]
+                   incr i
+               }
+           }
+       }
+       set nohs {}
+       set reins {}
+       set isfat [expr {[llength $dlist] > $maxwidth}]
+       if {$nhyperspace > 0 || $isfat} {
+           if {$ctxend > $n} break
+           # work out what to bring back and
+           # what we want to don't want to send into hyperspace
+           set room 1
+           for {set k $numcommits} {$k < $ctxend} {incr k} {
+               set x [lindex $displayorder $k]
+               set i [llsearch $dlist $x]
+               if {$i < 0} {
+                   set i [llength $dlist]
+                   lappend dlist $x
+               }
+               if {[lsearch -exact $nohs $x] < 0} {
+                   lappend nohs $x
+               }
+               if {$reins eq {} && $onscreen($x) < 0 && $room} {
+                   set reins [list $x $i]
+               }
+               set newp {}
+               if {[info exists commitlisted($x)]} {
+                   set right 0
+                   foreach p $parents($x) {
+                       if {[llsearch $dlist $p] < 0} {
+                           lappend newp $p
+                           if {[lsearch -exact $nohs $p] < 0} {
+                               lappend nohs $p
+                           }
+                           if {$reins eq {} && $onscreen($p) < 0 && $room} {
+                               set reins [list $p [expr {$i + $right}]]
+                           }
+                       }
+                       set right 1
+                   }
+               }
+               set l [lindex $dlist $i]
+               if {[llength $l] == 1} {
+                   set l $newp
+               } else {
+                   set j [lsearch -exact $l $x]
+                   set l [concat [lreplace $l $j $j] $newp]
+               }
+               set dlist [lreplace $dlist $i $i $l]
+               if {$room && $isfat && [llength $newp] <= 1} {
+                   set room 0

                }
                }

-               lappend mainline($id) $xi $y1 $xj $yb

            }
        }
            }
        }

+
+       set dlevel [drawslants $id $reins $nohs]
+       drawcommitline $dlevel
+       if {[clock clicks -milliseconds] >= $nextupdate
+           && $numcommits >= $ncmupdate} {
+           doupdate $reading
+           if {$stopped} break
+       }
+    }
+}
+
+# level here is an index in todo
+proc updatetodo {level noshortcut} {
+    global ncleft todo nnewparents
+    global commitlisted parents onscreen
+
+    set id [lindex $todo $level]
+    set olds {}
+    if {[info exists commitlisted($id)]} {
+       foreach p $parents($id) {
+           if {[lsearch -exact $olds $p] < 0} {
+               lappend olds $p
+           }
+       }
+    }
+    if {!$noshortcut && [llength $olds] == 1} {
+       set p [lindex $olds 0]
+       if {$ncleft($p) == 1 && [lsearch -exact $todo $p] < 0} {
+           set ncleft($p) 0
+           set todo [lreplace $todo $level $level $p]
+           set onscreen($p) 0
+           set nnewparents($id) 1
+           return 0
+       }
+    }
+
+    set todo [lreplace $todo $level $level]
+    set i $level
+    set n 0
+    foreach p $olds {
+       incr ncleft($p) -1
+       set k [lsearch -exact $todo $p]
+       if {$k < 0} {
+           set todo [linsert $todo $i $p]
+           set onscreen($p) 0
+           incr i
+           incr n
+       }

     }
     }

+    set nnewparents($id) $n
+
+    return 1

 }
 
 proc decidenext {{noread 0}} {
 }
 
 proc decidenext {{noread 0}} {

-    global parents children nchildren ncleft todo
-    global canv canv2 canv3 mainfont namefont canvy linespc
+    global ncleft todo

     global datemode cdate
     global commitinfo
     global datemode cdate
     global commitinfo

-    global currentparents oldlevel oldnlines oldtodo
-    global lineno lthickness
-
-    # remove the null entry if present
-    set nullentry [lsearch -exact $todo {}]
-    if {$nullentry >= 0} {
-       set todo [lreplace $todo $nullentry $nullentry]
-    }

 
     # choose which one to do next time around
     set todol [llength $todo]
 
     # choose which one to do next time around
     set todol [llength $todo]


@@ -1064,72 +1442,43 @@ proc decidenext {{noread 0}} {
        return -1
     }
 
        return -1
     }
 

-    # If we are reducing, put in a null entry
-    if {$todol < $oldnlines} {
-       if {$nullentry >= 0} {
-           set i $nullentry
-           while {$i < $todol
-                  && [lindex $oldtodo $i] == [lindex $todo $i]} {
-               incr i
-           }
-       } else {
-           set i $oldlevel
-           if {$level >= $i} {
-               incr i
-           }
-       }
-       if {$i < $todol} {
-           set todo [linsert $todo $i {}]
-           if {$level >= $i} {
-               incr level
-           }
-       }
-    }

     return $level
 }
 
 proc drawcommit {id} {
     global phase todo nchildren datemode nextupdate
     return $level
 }
 
 proc drawcommit {id} {
     global phase todo nchildren datemode nextupdate

-    global startcommits
+    global numcommits ncmupdate displayorder todo onscreen

 
     if {$phase != "incrdraw"} {
        set phase incrdraw
 
     if {$phase != "incrdraw"} {
        set phase incrdraw

-       set todo $id
-       set startcommits $id
+       set displayorder {}
+       set todo {}

        initgraph
        initgraph

-       drawcommitline 0
-       updatetodo 0 $datemode
-    } else {
-       if {$nchildren($id) == 0} {
-           lappend todo $id
-           lappend startcommits $id
-       }
-       set level [decidenext 1]
-       if {$level == {} || $id != [lindex $todo $level]} {
-           return
+    }
+    if {$nchildren($id) == 0} {
+       lappend todo $id
+       set onscreen($id) 0
+    }
+    set level [decidenext 1]
+    if {$level == {} || $id != [lindex $todo $level]} {
+       return
+    }
+    while 1 {
+       lappend displayorder [lindex $todo $level]
+       if {[updatetodo $level $datemode]} {
+           set level [decidenext 1]
+           if {$level == {}} break

        }
        }

-       while 1 {
-           drawslants $level
-           drawcommitline $level
-           if {[updatetodo $level $datemode]} {
-               set level [decidenext 1]
-               if {$level == {}} break
-           }
-           set id [lindex $todo $level]
-           if {![info exists commitlisted($id)]} {
-               break
-           }
-           if {[clock clicks -milliseconds] >= $nextupdate} {
-               doupdate
-               if {$stopped} break
-           }
+       set id [lindex $todo $level]
+       if {![info exists commitlisted($id)]} {
+           break

        }
     }
        }
     }

+    drawmore 1

 }
 
 proc finishcommits {} {
     global phase
 }
 
 proc finishcommits {} {
     global phase

-    global startcommits

     global canv mainfont ctext maincursor textcursor
 
     if {$phase != "incrdraw"} {
     global canv mainfont ctext maincursor textcursor
 
     if {$phase != "incrdraw"} {


@@ -1138,9 +1487,7 @@ proc finishcommits {} {
            -font $mainfont -tags textitems
        set phase {}
     } else {
            -font $mainfont -tags textitems
        set phase {}
     } else {

-       set level [decidenext]
-       drawslants $level
-       drawrest $level [llength $startcommits]
+       drawrest

     }
     . config -cursor $maincursor
     settextcursor $textcursor
     }
     . config -cursor $maincursor
     settextcursor $textcursor


@@ -1158,53 +1505,38 @@ proc settextcursor {c} {
 }
 
 proc drawgraph {} {
 }
 
 proc drawgraph {} {

-    global nextupdate startmsecs startcommits todo
+    global nextupdate startmsecs ncmupdate
+    global displayorder onscreen

 
 

-    if {$startcommits == {}} return
+    if {$displayorder == {}} return

     set startmsecs [clock clicks -milliseconds]
     set nextupdate [expr $startmsecs + 100]
     set startmsecs [clock clicks -milliseconds]
     set nextupdate [expr $startmsecs + 100]

+    set ncmupdate 1

     initgraph
     initgraph

-    set todo [lindex $startcommits 0]
-    drawrest 0 1
+    foreach id $displayorder {
+       set onscreen($id) 0
+    }
+    drawmore 0

 }
 
 }
 

-proc drawrest {level startix} {
+proc drawrest {} {

     global phase stopped redisplaying selectedline
     global phase stopped redisplaying selectedline

-    global datemode currentparents todo
-    global numcommits
-    global nextupdate startmsecs startcommits idline
+    global datemode todo displayorder
+    global numcommits ncmupdate
+    global nextupdate startmsecs

 
 

+    set level [decidenext]

     if {$level >= 0} {
        set phase drawgraph
     if {$level >= 0} {
        set phase drawgraph

-       set startid [lindex $startcommits $startix]
-       set startline -1
-       if {$startid != {}} {
-           set startline $idline($startid)
-       }

        while 1 {
        while 1 {

-           if {$stopped} break
-           drawcommitline $level
+           lappend displayorder [lindex $todo $level]

            set hard [updatetodo $level $datemode]
            set hard [updatetodo $level $datemode]

-           if {$numcommits == $startline} {
-               lappend todo $startid
-               set hard 1
-               incr startix
-               set startid [lindex $startcommits $startix]
-               set startline -1
-               if {$startid != {}} {
-                   set startline $idline($startid)
-               }
-           }

            if {$hard} {
                set level [decidenext]
                if {$level < 0} break
            if {$hard} {
                set level [decidenext]
                if {$level < 0} break

-               drawslants $level
-           }
-           if {[clock clicks -milliseconds] >= $nextupdate} {
-               update
-               incr nextupdate 100

            }
        }
            }
        }

+       drawmore 0

     }
     set phase {}
     set drawmsecs [expr [clock clicks -milliseconds] - $startmsecs]
     }
     set phase {}
     set drawmsecs [expr [clock clicks -milliseconds] - $startmsecs]


@@ -1704,14 +2036,49 @@ proc selcanvline {w x y} {
     selectline $l 1
 }
 
     selectline $l 1
 }
 

+proc commit_descriptor {p} {
+    global commitinfo
+    set l "..."
+    if {[info exists commitinfo($p)]} {
+       set l [lindex $commitinfo($p) 0]
+    }
+    return "$p ($l)"
+}
+
+# append some text to the ctext widget, and make any SHA1 ID
+# that we know about be a clickable link.
+proc appendwithlinks {text} {
+    global ctext idline linknum
+
+    set start [$ctext index "end - 1c"]
+    $ctext insert end $text
+    $ctext insert end "\n"
+    set links [regexp -indices -all -inline {[0-9a-f]{40}} $text]
+    foreach l $links {
+       set s [lindex $l 0]
+       set e [lindex $l 1]
+       set linkid [string range $text $s $e]
+       if {![info exists idline($linkid)]} continue
+       incr e
+       $ctext tag add link "$start + $s c" "$start + $e c"
+       $ctext tag add link$linknum "$start + $s c" "$start + $e c"
+       $ctext tag bind link$linknum <1> [list selectline $idline($linkid) 1]
+       incr linknum
+    }
+    $ctext tag conf link -foreground blue -underline 1
+    $ctext tag bind link <Enter> { %W configure -cursor hand2 }
+    $ctext tag bind link <Leave> { %W configure -cursor $curtextcursor }
+}
+

 proc selectline {l isnew} {
     global canv canv2 canv3 ctext commitinfo selectedline
     global lineid linehtag linentag linedtag
 proc selectline {l isnew} {
     global canv canv2 canv3 ctext commitinfo selectedline
     global lineid linehtag linentag linedtag

-    global canvy0 linespc parents nparents
+    global canvy0 linespc parents nparents children

     global cflist currentid sha1entry
     global cflist currentid sha1entry

-    global commentend idtags idline
+    global commentend idtags idline linknum

 
     $canv delete hover
 
     $canv delete hover

+    normalline

     if {![info exists lineid($l)] || ![info exists linehtag($l)]} return
     $canv delete secsel
     set t [eval $canv create rect [$canv bbox $linehtag($l)] -outline {{}} \
     if {![info exists lineid($l)] || ![info exists linehtag($l)]} return
     $canv delete secsel
     set t [eval $canv create rect [$canv bbox $linehtag($l)] -outline {{}} \


@@ -1775,6 +2142,7 @@ proc selectline {l isnew} {
 
     $ctext conf -state normal
     $ctext delete 0.0 end
 
     $ctext conf -state normal
     $ctext delete 0.0 end

+    set linknum 0

     $ctext mark set fmark.0 0.0
     $ctext mark gravity fmark.0 left
     set info $commitinfo($id)
     $ctext mark set fmark.0 0.0
     $ctext mark gravity fmark.0 left
     set info $commitinfo($id)


@@ -1788,40 +2156,22 @@ proc selectline {l isnew} {
        $ctext insert end "\n"
     }
  
        $ctext insert end "\n"
     }
  

-    set commentstart [$ctext index "end - 1c"]

     set comment {}
     set comment {}

-    foreach p $parents($id) {
-       set l "..."
-       if {[info exists commitinfo($p)]} {
-           set l [lindex $commitinfo($p) 0]
-           if {[string length $l] > 32} {
-               set l "[string range $l 0 28] ..."
-           }
+    if {[info exists parents($id)]} {
+       foreach p $parents($id) {
+           append comment "Parent: [commit_descriptor $p]\n"
+       }
+    }
+    if {[info exists children($id)]} {
+       foreach c $children($id) {
+           append comment "Child:  [commit_descriptor $c]\n"

        }
        }

-       append comment "Parent: $p  ($l)\n"

     }
     append comment "\n"
     append comment [lindex $info 5]
     }
     append comment "\n"
     append comment [lindex $info 5]

-    $ctext insert end $comment
-    $ctext insert end "\n"

 
     # make anything that looks like a SHA1 ID be a clickable link
 
     # make anything that looks like a SHA1 ID be a clickable link

-    set links [regexp -indices -all -inline {[0-9a-f]{40}} $comment]
-    set i 0
-    foreach l $links {
-       set s [lindex $l 0]
-       set e [lindex $l 1]
-       set linkid [string range $comment $s $e]
-       if {![info exists idline($linkid)]} continue
-       incr e
-       $ctext tag add link "$commentstart + $s c" "$commentstart + $e c"
-       $ctext tag add link$i "$commentstart + $s c" "$commentstart + $e c"
-       $ctext tag bind link$i <1> [list selectline $idline($linkid) 1]
-       incr i
-    }
-    $ctext tag conf link -foreground blue -underline 1
-    $ctext tag bind link <Enter> { %W configure -cursor hand2 }
-    $ctext tag bind link <Leave> { %W configure -cursor $curtextcursor }
+    appendwithlinks $comment

 
     $ctext tag delete Comments
     $ctext tag remove found 1.0 end
 
     $ctext tag delete Comments
     $ctext tag remove found 1.0 end


@@ -2631,12 +2981,13 @@ proc listboxsel {} {
 
 proc setcoords {} {
     global linespc charspc canvx0 canvy0 mainfont
 
 proc setcoords {} {
     global linespc charspc canvx0 canvy0 mainfont

-    global xspc1 xspc2
+    global xspc1 xspc2 lthickness

 
     set linespc [font metrics $mainfont -linespace]
     set charspc [font measure $mainfont "m"]
     set canvy0 [expr 3 + 0.5 * $linespc]
     set canvx0 [expr 3 + 0.5 * $linespc]
 
     set linespc [font metrics $mainfont -linespace]
     set charspc [font measure $mainfont "m"]
     set canvy0 [expr 3 + 0.5 * $linespc]
     set canvx0 [expr 3 + 0.5 * $linespc]

+    set lthickness [expr {int($linespc / 9) + 1}]

     set xspc1(0) $linespc
     set xspc2 $linespc
 }
     set xspc1(0) $linespc
     set xspc2 $linespc
 }


@@ -2796,15 +3147,102 @@ proc linehover {} {
     $canv raise $t
 }
 
     $canv raise $t
 }
 

+proc clickisonarrow {id y} {
+    global mainline mainlinearrow sidelines lthickness
+
+    set thresh [expr {2 * $lthickness + 6}]
+    if {[info exists mainline($id)]} {
+       if {$mainlinearrow($id) ne "none"} {
+           if {abs([lindex $mainline($id) 1] - $y) < $thresh} {
+               return "up"
+           }
+       }
+    }
+    if {[info exists sidelines($id)]} {
+       foreach ls $sidelines($id) {
+           set coords [lindex $ls 0]
+           set arrow [lindex $ls 2]
+           if {$arrow eq "first" || $arrow eq "both"} {
+               if {abs([lindex $coords 1] - $y) < $thresh} {
+                   return "up"
+               }
+           }
+           if {$arrow eq "last" || $arrow eq "both"} {
+               if {abs([lindex $coords end] - $y) < $thresh} {
+                   return "down"
+               }
+           }
+       }
+    }
+    return {}
+}
+
+proc arrowjump {id dirn y} {
+    global mainline sidelines canv
+
+    set yt {}
+    if {$dirn eq "down"} {
+       if {[info exists mainline($id)]} {
+           set y1 [lindex $mainline($id) 1]
+           if {$y1 > $y} {
+               set yt $y1
+           }
+       }
+       if {[info exists sidelines($id)]} {
+           foreach ls $sidelines($id) {
+               set y1 [lindex $ls 0 1]
+               if {$y1 > $y && ($yt eq {} || $y1 < $yt)} {
+                   set yt $y1
+               }
+           }
+       }
+    } else {
+       if {[info exists sidelines($id)]} {
+           foreach ls $sidelines($id) {
+               set y1 [lindex $ls 0 end]
+               if {$y1 < $y && ($yt eq {} || $y1 > $yt)} {
+                   set yt $y1
+               }
+           }
+       }
+    }
+    if {$yt eq {}} return
+    set ymax [lindex [$canv cget -scrollregion] 3]
+    if {$ymax eq {} || $ymax <= 0} return
+    set view [$canv yview]
+    set yspan [expr {[lindex $view 1] - [lindex $view 0]}]
+    set yfrac [expr {$yt / $ymax - $yspan / 2}]
+    if {$yfrac < 0} {
+       set yfrac 0
+    }
+    $canv yview moveto $yfrac
+}
+

 proc lineclick {x y id isnew} {
 proc lineclick {x y id isnew} {

-    global ctext commitinfo children cflist canv
+    global ctext commitinfo children cflist canv thickerline

 
     unmarkmatches
     unselectline
 
     unmarkmatches
     unselectline

+    normalline
+    $canv delete hover
+    # draw this line thicker than normal
+    drawlines $id 1
+    set thickerline $id

     if {$isnew} {
     if {$isnew} {

-       addtohistory [list lineclick $x $x $id 0]
+       set ymax [lindex [$canv cget -scrollregion] 3]
+       if {$ymax eq {}} return
+       set yfrac [lindex [$canv yview] 0]
+       set y [expr {$y + $yfrac * $ymax}]
+    }
+    set dirn [clickisonarrow $id $y]
+    if {$dirn ne {}} {
+       arrowjump $id $dirn $y
+       return
+    }
+
+    if {$isnew} {
+       addtohistory [list lineclick $x $y $id 0]

     }
     }

-    $canv delete hover

     # fill the details pane with info about this line
     $ctext conf -state normal
     $ctext delete 0.0 end
     # fill the details pane with info about this line
     $ctext conf -state normal
     $ctext delete 0.0 end


@@ -2837,6 +3275,14 @@ proc lineclick {x y id isnew} {
     $cflist delete 0 end
 }
 
     $cflist delete 0 end
 }
 

+proc normalline {} {
+    global thickerline
+    if {[info exists thickerline]} {
+       drawlines $thickerline 0
+       unset thickerline
+    }
+}
+

 proc selbyid {id} {
     global idline
     if {[info exists idline($id)]} {
 proc selbyid {id} {
     global idline
     if {[info exists idline($id)]} {


@@ -3030,7 +3476,6 @@ proc mktag {} {
 
 proc domktag {} {
     global mktagtop env tagids idtags
 
 proc domktag {} {
     global mktagtop env tagids idtags

-    global idpos idline linehtag canv selectedline

 
     set id [$mktagtop.sha1 get]
     set tag [$mktagtop.tag get]
 
     set id [$mktagtop.sha1 get]
     set tag [$mktagtop.tag get]


@@ -3055,6 +3500,13 @@ proc domktag {} {
 
     set tagids($tag) $id
     lappend idtags($id) $tag
 
     set tagids($tag) $id
     lappend idtags($id) $tag

+    redrawtags $id
+}
+
+proc redrawtags {id} {
+    global canv linehtag idline idpos selectedline
+
+    if {![info exists idline($id)]} return

     $canv delete tag.$id
     set xt [eval drawtags $id $idpos($id)]
     $canv coords $linehtag($idline($id)) $xt [lindex $idpos($id) 2]
     $canv delete tag.$id
     set xt [eval drawtags $id $idpos($id)]
     $canv coords $linehtag($idline($id)) $xt [lindex $idpos($id) 2]


@@ -3130,6 +3582,68 @@ proc wrcomcan {} {
     unset wrcomtop
 }
 
     unset wrcomtop
 }
 

+proc listrefs {id} {
+    global idtags idheads idotherrefs
+
+    set x {}
+    if {[info exists idtags($id)]} {
+       set x $idtags($id)
+    }
+    set y {}
+    if {[info exists idheads($id)]} {
+       set y $idheads($id)
+    }
+    set z {}
+    if {[info exists idotherrefs($id)]} {
+       set z $idotherrefs($id)
+    }
+    return [list $x $y $z]
+}
+
+proc rereadrefs {} {
+    global idtags idheads idotherrefs
+    global tagids headids otherrefids
+
+    set refids [concat [array names idtags] \
+                   [array names idheads] [array names idotherrefs]]
+    foreach id $refids {
+       if {![info exists ref($id)]} {
+           set ref($id) [listrefs $id]
+       }
+    }
+    foreach v {tagids idtags headids idheads otherrefids idotherrefs} {
+       catch {unset $v}
+    }
+    readrefs
+    set refids [lsort -unique [concat $refids [array names idtags] \
+                       [array names idheads] [array names idotherrefs]]]
+    foreach id $refids {
+       set v [listrefs $id]
+       if {![info exists ref($id)] || $ref($id) != $v} {
+           redrawtags $id
+       }
+    }
+}
+
+proc showtag {tag isnew} {
+    global ctext cflist tagcontents tagids linknum
+
+    if {$isnew} {
+       addtohistory [list showtag $tag 0]
+    }
+    $ctext conf -state normal
+    $ctext delete 0.0 end
+    set linknum 0
+    if {[info exists tagcontents($tag)]} {
+       set text $tagcontents($tag)
+    } else {
+       set text "Tag: $tag\nId:  $tagids($tag)"
+    }
+    appendwithlinks $text
+    $ctext conf -state disabled
+    $cflist delete 0 end
+}
+

 proc doquit {} {
     global stopped
     set stopped 100
 proc doquit {} {
     global stopped
     set stopped 100


@@ -3147,6 +3661,7 @@ set textfont {Courier 9}
 set findmergefiles 0
 set gaudydiff 0
 set maxgraphpct 50
 set findmergefiles 0
 set gaudydiff 0
 set maxgraphpct 50

+set maxwidth 16

 
 set colors {green red blue magenta darkgrey brown orange}
 
 
 set colors {green red blue magenta darkgrey brown orange}