+method _blameparent {} {
+ global nullid
+
+ set dat [_get_click_amov_info $this]
+ if {$dat ne {}} {
+ set cmit [lindex $dat 0]
+ set new_path [lindex $dat 1]
+
+ # Allow using Blame Parent on lines modified in the working copy
+ if {$cmit eq $nullid} {
+ set parent_ref "HEAD"
+ } else {
+ set parent_ref "$cmit^"
+ }
+ if {[catch {set cparent [git rev-parse --verify $parent_ref]} err]} {
+ error_popup [strcat [mc "Cannot find parent commit:"] "\n\n$err"]
+ return;
+ }
+
+ _kill $this
+
+ # Generate a diff between the commit and its parent,
+ # and use the hunks to update the line number.
+ # Request zero context to simplify calculations.
+ if {$cmit eq $nullid} {
+ set diffcmd [list diff-index --unified=0 $cparent -- $new_path]
+ } else {
+ set diffcmd [list diff-tree --unified=0 $cparent $cmit -- $new_path]
+ }
+ if {[catch {set fd [eval git_read $diffcmd]} 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}