git-gui: Better positioning in Blame Parent Commit

[git.git] / lib / blame.tcl

diff --git a/lib/blame.tcl b/lib/blame.tcl
index c8975cfecdbe5dd4cf00a458d5b07a6ff9840f8c..1106975775e86cea028b42977521ea255d698468 100644 (file)
--- a/lib/blame.tcl
+++ b/lib/blame.tcl
@@ -262,6 +262,9 @@ constructor new {i_commit i_path} {
        $w.ctxm add command \
                -label [mc "Show History Context"] \
                -command [cb _gitkcommit]
+       $w.ctxm add command \
+               -label [mc "Blame Parent Commit"] \
+               -command [cb _blameparent]
 
        foreach i $w_columns {
                for {set g 0} {$g < [llength $group_colors]} {incr g} {
@@ -790,19 +793,27 @@ method _load_commit {cur_w cur_d pos} {
        set lno [lindex [split [$cur_w index $pos] .] 0]
        set dat [lindex $line_data $lno]
        if {$dat ne {}} {
-               lappend history [list \
-                       $commit $path \
-                       $highlight_column \
-                       $highlight_line \
-                       [lindex [$w_file xview] 0] \
-                       [lindex [$w_file yview] 0] \
-                       ]
-               set commit [lindex $dat 0]
-               set path   [lindex $dat 1]
-               _load $this [list [lindex $dat 2]]
+               _load_new_commit $this  \
+                       [lindex $dat 0] \
+                       [lindex $dat 1] \
+                       [list [lindex $dat 2]]
        }
 }
 
+method _load_new_commit {new_commit new_path jump} {
+       lappend history [list \
+               $commit $path \
+               $highlight_column \
+               $highlight_line \
+               [lindex [$w_file xview] 0] \
+               [lindex [$w_file yview] 0] \
+               ]
+
+       set commit $new_commit
+       set path   $new_path
+       _load $this $jump
+}
+
 method _showcommit {cur_w lno} {
        global repo_config
        variable active_color
@@ -969,6 +980,80 @@ method _gitkcommit {} {
        }
 }
 
+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 $fd} }
+
 method _show_tooltip {cur_w pos} {
        if {$tooltip_wm ne {}} {
                _open_tooltip $this $cur_w