+method _format_offset_date {base offset} {
+ set exval [expr {$base + $offset*24*60*60}]
+ return [clock format $exval -format {%Y-%m-%d}]
+}
+
+method _gitkcommit {} {
+ set dat [_get_click_amov_info $this]
+ if {$dat ne {}} {
+ set cmit [lindex $dat 0]
+ set radius [get_config gui.blamehistoryctx]
+ set cmdline [list --select-commit=$cmit]
+
+ if {$radius > 0} {
+ set author_time {}
+ set committer_time {}
+
+ catch {set author_time $header($cmit,author-time)}
+ catch {set committer_time $header($cmit,committer-time)}
+
+ if {$committer_time eq {}} {
+ set committer_time $author_time
+ }
+
+ set after_time [_format_offset_date $this $committer_time [expr {-$radius}]]
+ set before_time [_format_offset_date $this $committer_time $radius]
+
+ lappend cmdline --after=$after_time --before=$before_time
+ }
+
+ lappend cmdline $cmit
+
+ set base_rev "HEAD"
+ if {$commit ne {}} {
+ set base_rev $commit
+ }
+
+ if {$base_rev ne $cmit} {
+ lappend cmdline $base_rev
+ }
+
+ do_gitk $cmdline
+ }
+}
+
+method _blameparent {} {
+ set dat [_get_click_amov_info $this]
+ if {$dat ne {}} {
+ set cmit [lindex $dat 0]
+ set new_path [lindex $dat 1]
+
+ if {[catch {set cparent [git rev-parse --verify "$cmit^"]}]} {
+ error_popup [strcat [mc "Cannot find parent commit:"] "\n\n$err"]
+ return;
+ }
+
+ _kill $this
+
+ # Generate a diff between the commit and its parent,
+ # and use the hunks to update the line number.
+ # Request zero context to simplify calculations.
+ if {[catch {set fd [eval git_read diff-tree \
+ --unified=0 $cparent $cmit $new_path]} err]} {
+ $status stop [mc "Unable to display parent"]
+ error_popup [strcat [mc "Error loading diff:"] "\n\n$err"]
+ return
+ }
+
+ set r_orig_line [lindex $dat 2]
+
+ fconfigure $fd \
+ -blocking 0 \
+ -encoding binary \
+ -translation binary
+ fileevent $fd readable [cb _read_diff_load_commit \
+ $fd $cparent $new_path $r_orig_line]
+ set current_fd $fd
+ }
+}
+
+method _read_diff_load_commit {fd cparent new_path tline} {
+ if {$fd ne $current_fd} {
+ catch {close $fd}
+ return
+ }
+
+ while {[gets $fd line] >= 0} {
+ if {[regexp {^@@ -(\d+)(,(\d+))? \+(\d+)(,(\d+))? @@} $line line \
+ old_line osz old_size new_line nsz new_size]} {
+
+ if {$osz eq {}} { set old_size 1 }
+ if {$nsz eq {}} { set new_size 1 }
+
+ if {$new_line <= $tline} {
+ if {[expr {$new_line + $new_size}] > $tline} {
+ # Target line within the hunk
+ set line_shift [expr {
+ ($new_size-$old_size)*($tline-$new_line)/$new_size
+ }]
+ } else {
+ set line_shift [expr {$new_size-$old_size}]
+ }
+
+ set r_orig_line [expr {$r_orig_line - $line_shift}]
+ }
+ }
+ }
+
+ if {[eof $fd]} {
+ close $fd;
+ set current_fd {}
+
+ _load_new_commit $this \
+ $cparent \
+ $new_path \
+ [list $r_orig_line]
+ }
+} ifdeleted { catch {close $fd} }
+