+ show_diff $next_diff_p $next_diff_w {}
+}
+
+proc find_anchor_pos {lst name} {
+ set lid [lsearch -sorted -exact $lst $name]
+
+ if {$lid == -1} {
+ set lid 0
+ foreach lname $lst {
+ if {$lname >= $name} break
+ incr lid
+ }
+ }
+
+ return $lid
+}
+
+proc find_file_from {flist idx delta path mmask} {
+ global file_states
+
+ set len [llength $flist]
+ while {$idx >= 0 && $idx < $len} {
+ set name [lindex $flist $idx]
+
+ if {$name ne $path && [info exists file_states($name)]} {
+ set state [lindex $file_states($name) 0]
+
+ if {$mmask eq {} || [regexp $mmask $state]} {
+ return $idx
+ }
+ }
+
+ incr idx $delta
+ }
+
+ return {}
+}
+
+proc find_next_diff {w path {lno {}} {mmask {}}} {
+ global next_diff_p next_diff_w next_diff_i
+ global file_lists ui_index ui_workdir
+
+ set flist $file_lists($w)
+ if {$lno eq {}} {
+ set lno [find_anchor_pos $flist $path]
+ } else {
+ incr lno -1
+ }
+
+ if {$mmask ne {} && ![regexp {(^\^)|(\$$)} $mmask]} {
+ if {$w eq $ui_index} {
+ set mmask "^$mmask"
+ } else {
+ set mmask "$mmask\$"
+ }
+ }
+
+ set idx [find_file_from $flist $lno 1 $path $mmask]
+ if {$idx eq {}} {
+ incr lno -1
+ set idx [find_file_from $flist $lno -1 $path $mmask]
+ }
+
+ if {$idx ne {}} {
+ set next_diff_w $w
+ set next_diff_p [lindex $flist $idx]
+ set next_diff_i [expr {$idx+1}]
+ return 1
+ } else {
+ return 0
+ }
+}
+
+proc next_diff_after_action {w path {lno {}} {mmask {}}} {
+ global current_diff_path
+
+ if {$path ne $current_diff_path} {
+ return {}
+ } elseif {[find_next_diff $w $path $lno $mmask]} {
+ return {next_diff;}
+ } else {
+ return {reshow_diff;}
+ }
+}
+
+proc select_first_diff {} {
+ global ui_workdir
+
+ if {[find_next_diff $ui_workdir {} 1 {^_?U}] ||
+ [find_next_diff $ui_workdir {} 1 {[^O]$}]} {
+ next_diff
+ }