gitk: Fix Update menu item

This just does the simple thing of resetting everything, reading all
the commits, and redoing the whole layout from scratch.  Hopefully
things are now fast enough that this simple approach is acceptable.
Also, this fits in better with future plans for adding the ability
to restrict the tree to just a few files and then expand back to
the whole tree.

Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -61,16 +61,8 @@ proc start_rev_list {rlargs} {
 }
 
 proc getcommits {rargs} {
-    global oldcommits commits phase canv mainfont env
+    global phase canv mainfont
 
-    # check that we can find a .git directory somewhere...
-    set gitdir [gitdir]
-    if {![file isdirectory $gitdir]} {
-	error_popup "Cannot find the git directory \"$gitdir\"."
-	exit 1
-    }
-    set oldcommits {}
-    set commits {}
     set phase getcommits
     start_rev_list [parse_args $rargs]
     $canv delete all
@@ -79,8 +71,8 @@ proc getcommits {rargs} {
 }
 
 proc getcommitlines {commfd}  {
-    global oldcommits commits parents cdate children nchildren
-    global commitlisted phase nextupdate
+    global parents cdate children nchildren
+    global commitlisted nextupdate
     global stopped leftover
     global canv
 
@@ -140,7 +132,6 @@ proc getcommitlines {commfd}  {
 	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
 	parsecommit $id $cmit 1 [lrange $ids 1 end]
 	drawcommit $id 1
@@ -177,93 +168,18 @@ proc readcommit {id} {
 }
 
 proc updatecommits {rargs} {
-    global commitlisted commfd phase
-    global startmsecs nextupdate ncmupdate
-    global idtags idheads idotherrefs
-    global leftover
-    global parsed_args
-    global canv mainfont
-    global oldcommits commits
-    global parents nchildren children
-
-    set old_args $parsed_args
-    parse_args $rargs
-
-    if {$phase == "getcommits" || $phase == "incrdraw"} {
-	# havent read all the old commits, just start again from scratch
-	stopfindproc
-	set oldcommits {}
-	set commits {}
-	foreach v {children nchildren parents commitlisted commitinfo
-		   selectedline matchinglines treediffs
-		   mergefilelist currentid rowtextx} {
-	    global $v
-	    catch {unset $v}
-	}
-	readrefs
-	if {$phase == "incrdraw"} {
-	    allcanvs delete all
-	    $canv create text 3 3 -anchor nw -text "Reading commits..." \
-		-font $mainfont -tags textitems
-	    set phase getcommits
-	}
-	start_rev_list $parsed_args
-	return
-    }
-
-    foreach id $old_args {
-	if {![regexp {^[0-9a-f]{40}$} $id]} continue
-	if {[info exists oldref($id)]} continue
-	set oldref($id) $id
-	lappend ignoreold "^$id"
-    }
-    foreach id $parsed_args {
-	if {![regexp {^[0-9a-f]{40}$} $id]} continue
-	if {[info exists ref($id)]} continue
-	set ref($id) $id
-	lappend ignorenew "^$id"
-    }
-
-    foreach a $old_args {
-	if {![info exists ref($a)]} {
-	    lappend ignorenew $a
-	}
-    }
-
-    set phase updatecommits
-    set oldcommits $commits
-    set commits {}
-    set removed_commits [split [eval exec git-rev-list $ignorenew] "\n" ]
-    if {[llength $removed_commits] > 0} {
-	allcanvs delete all
-	foreach c $removed_commits {
-	    set i [lsearch -exact $oldcommits $c]
-	    if {$i >= 0} {
-		set oldcommits [lreplace $oldcommits $i $i]
-		unset commitlisted($c)
-		foreach p $parents($c) {
-		    if {[info exists nchildren($p)]} {
-			set j [lsearch -exact $children($p) $c]
-			if {$j >= 0} {
-			    set children($p) [lreplace $children($p) $j $j]
-			    incr nchildren($p) -1
-			}
-		    }
-		}
-	    }
-	}
-	set phase removecommits
-    }
-
-    set args {}
-    foreach a $parsed_args {
-	if {![info exists oldref($a)]} {
-	    lappend args $a
-	}
+    stopfindproc
+    foreach v {children nchildren parents nparents commitlisted
+	commitinfo colormap selectedline matchinglines treediffs
+	mergefilelist currentid rowtextx commitrow lineid
+	rowidlist rowoffsets idrowranges idrangedrawn iddrawn
+	linesegends crossings cornercrossings} {
+	global $v
+	catch {unset $v}
     }
-
+    allcanvs delete all
     readrefs
-    start_rev_list [concat $ignoreold $args]
+    getcommits $rargs
 }
 
 proc updatechildren {id olds} {
@@ -1456,7 +1372,7 @@ proc clear_display {} {
 }
 
 proc assigncolor {id} {
-    global colormap commcolors colors nextcolor
+    global colormap colors nextcolor
     global parents nparents children nchildren
     global cornercrossings crossings
 
@@ -1533,10 +1449,6 @@ proc initgraph {} {
     allcanvs delete all
     set nextcolor 0
     set numcommits 0
-    foreach v {colormap cornercrossings	crossings lineid} {
-	global $v
-	catch {unset $v}
-    }
 }
 
 proc bindline {t id} {
@@ -1696,22 +1608,11 @@ proc drawcommit {id reading} {
 }
 
 proc finishcommits {} {
-    global phase oldcommits commits
+    global phase
     global canv mainfont ctext maincursor textcursor
-    global parents todo
 
-    if {$phase == "incrdraw" || $phase == "removecommits"} {
-	foreach id $oldcommits {
-	    lappend commits $id
-	    drawcommit $id 0
-	}
-	set oldcommits {}
+    if {$phase == "incrdraw"} {
 	drawrest
-    } elseif {$phase == "updatecommits"} {
-	# there were no new commits, in fact
-	set commits $oldcommits
-	set oldcommits {}
-	set phase {}
     } else {
 	$canv delete all
 	$canv create text 3 3 -anchor nw -text "No commits selected" \
@@ -3773,6 +3674,13 @@ foreach arg $argv {
     }
 }
 
+# check that we can find a .git directory somewhere...
+set gitdir [gitdir]
+if {![file isdirectory $gitdir]} {
+    error_popup "Cannot find the git directory \"$gitdir\"."
+    exit 1
+}
+
 set history {}
 set historyindex 0