Add a menu item to invoke full copy detection in blame.

Add a context menu item to invoke blame -C -C -C on a chunk
of the file. The results are used to update the 'original
location' column of the blame display.

The chunk is computed as the smallest line range that covers
both the 'last change' and 'original location' ranges of the
line that was clicked to open the menu.

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

lib/blame.tcl

@@ -256,6 +256,9 @@ constructor new {i_commit i_path} {
 	$w.ctxm add command \
 		-label [mc "Copy Commit"] \
 		-command [cb _copycommit]
+	$w.ctxm add command \
+		-label [mc "Do Full Copy Detection"] \
+		-command [cb _fullcopyblame]
 
 	foreach i $w_columns {
 		for {set g 0} {$g < [llength $group_colors]} {incr g} {
@@ -708,6 +711,72 @@ method _read_blame {fd cur_w cur_d} {
 	}
 } ifdeleted { catch {close $fd} }
 
+method _find_commit_bound {data_list start_idx delta} {
+	upvar #0 $data_list line_data
+	set pos $start_idx
+	set limit       [expr {[llength $line_data] - 1}]
+	set base_commit [lindex $line_data $pos 0]
+
+	while {$pos > 0 && $pos < $limit} {
+		set new_pos [expr {$pos + $delta}]
+		if {[lindex $line_data $new_pos 0] ne $base_commit} {
+			return $pos
+		}
+
+		set pos $new_pos
+	}
+
+	return $pos
+}
+
+method _fullcopyblame {} {
+	if {$current_fd ne {}} {
+		tk_messageBox \
+			-icon error \
+			-type ok \
+			-title [mc "Busy"] \
+			-message [mc "Annotation process is already running."]
+
+		return
+	}
+
+	# Switches for original location detection
+	set threshold [get_config gui.copyblamethreshold]
+	set original_options [list -C -C "-C$threshold"]
+
+	if {[git-version >= 1.5.3]} {
+		lappend original_options -w ; # ignore indentation changes
+	}
+
+	# Find the line range
+	set pos @$::cursorX,$::cursorY
+	set lno [lindex [split [$::cursorW index $pos] .] 0]
+	set min_amov_lno [_find_commit_bound $this @amov_data $lno -1]
+	set max_amov_lno [_find_commit_bound $this @amov_data $lno 1]
+	set min_asim_lno [_find_commit_bound $this @asim_data $lno -1]
+	set max_asim_lno [_find_commit_bound $this @asim_data $lno 1]
+
+	if {$min_asim_lno < $min_amov_lno} {
+		set min_amov_lno $min_asim_lno
+	}
+
+	if {$max_asim_lno > $max_amov_lno} {
+		set max_amov_lno $max_asim_lno
+	}
+
+	lappend original_options -L "$min_amov_lno,$max_amov_lno"
+
+	# Clear lines
+	for {set i $min_amov_lno} {$i <= $max_amov_lno} {incr i} {
+		lset amov_data $i [list ]
+	}
+
+	# Start the back-end process
+	_exec_blame $this $w_amov @amov_data \
+		$original_options \
+		[mc "Running thorough copy detection..."]
+}
+
 method _click {cur_w pos} {
 	set lno [lindex [split [$cur_w index $pos] .] 0]
 	_showcommit $this $cur_w $lno