git-gui: allow undoing last revert

Accidental clicks on the revert hunk/lines buttons can cause loss of work, and can be frustrating. So, allow undoing the last revert. Right now, a stack or deque are not being used for the sake of simplicity, so only one undo is possible. Any reverts before the previous one are lost. Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>

Pratyush Yadav committed Aug 26, 2019 at 01:43 UTC a4fa2f0a4c1a1ef7f2987fb9d38342fcaad78a75
2 files changed +66 -5
git-gui.sh
+17 -1
@@ -1350,6 +1350,8 @@ set is_submodule_diff 0
1350 set is_conflict_diff 0
1351 set selected_commit_type new
1352 set diff_empty_count 0
1353 +set last_revert {}
1354 +set last_revert_enc {}
1355
1356 set nullid "0000000000000000000000000000000000000000"
1357 set nullid2 "0000000000000000000000000000000000000001"
@@ -3601,6 +3603,11 @@ $ctxm add command \
3603 -command {apply_or_revert_range_or_line $cursorX $cursorY 1; do_rescan}
3604 set ui_diff_revertline [$ctxm index last]
3605 lappend diff_actions [list $ctxm entryconf $ui_diff_revertline -state]
3606 +$ctxm add command \
3607 + -label [mc "Undo Last Revert"] \
3608 + -command {undo_last_revert; do_rescan}
3609 +set ui_diff_undorevert [$ctxm index last]
3610 +lappend diff_actions [list $ctxm entryconf $ui_diff_undorevert -state]
3611 $ctxm add separator
3612 $ctxm add command \
3613 -label [mc "Show Less Context"] \
@@ -3680,7 +3687,7 @@ proc has_textconv {path} {
3687 }
3688
3689 proc popup_diff_menu {ctxm ctxmmg ctxmsm x y X Y} {
3683 - global current_diff_path file_states
3690 + global current_diff_path file_states last_revert
3691 set ::cursorX $x
3692 set ::cursorY $y
3693 if {[info exists file_states($current_diff_path)]} {
@@ -3694,6 +3701,7 @@ proc popup_diff_menu {ctxm ctxmmg ctxmsm x y X Y} {
3701 tk_popup $ctxmsm $X $Y
3702 } else {
3703 set has_range [expr {[$::ui_diff tag nextrange sel 0.0] != {}}]
3704 + set u [mc "Undo Last Revert"]
3705 if {$::ui_index eq $::current_diff_side} {
3706 set l [mc "Unstage Hunk From Commit"]
3707 set h [mc "Revert Hunk"]
@@ -3739,12 +3747,20 @@ proc popup_diff_menu {ctxm ctxmmg ctxmsm x y X Y} {
3747 }
3748 }
3749
3750 + if {$last_revert eq {}} {
3751 + set undo_state disabled
3752 + } else {
3753 + set undo_state normal
3754 + }
3755 +
3756 $ctxm entryconf $::ui_diff_applyhunk -state $s -label $l
3757 $ctxm entryconf $::ui_diff_applyline -state $s -label $t
3758 $ctxm entryconf $::ui_diff_revertline -state $revert_state \
3759 -label $r
3760 $ctxm entryconf $::ui_diff_reverthunk -state $revert_state \
3761 -label $h
3762 + $ctxm entryconf $::ui_diff_undorevert -state $undo_state \
3763 + -label $u
3764
3765 tk_popup $ctxm $X $Y
3766 }
lib/diff.tcl
+49 -4
@@ -569,7 +569,7 @@ proc read_diff {fd conflict_size cont_info} {
569
570 proc apply_or_revert_hunk {x y revert} {
571 global current_diff_path current_diff_header current_diff_side
572 - global ui_diff ui_index file_states
572 + global ui_diff ui_index file_states last_revert last_revert_enc
573
574 if {$current_diff_path eq {} || $current_diff_header eq {}} return
575 if {![lock_index apply_hunk]} return
@@ -610,18 +610,25 @@ proc apply_or_revert_hunk {x y revert} {
610 set e_lno end
611 }
612
613 + set wholepatch "$current_diff_header[$ui_diff get $s_lno $e_lno]"
614 +
615 if {[catch {
616 set enc [get_path_encoding $current_diff_path]
617 set p [eval git_write $apply_cmd]
618 fconfigure $p -translation binary -encoding $enc
617 - puts -nonewline $p $current_diff_header
618 - puts -nonewline $p [$ui_diff get $s_lno $e_lno]
619 + puts -nonewline $p $wholepatch
620 close $p} err]} {
621 error_popup "$failed_msg\n\n$err"
622 unlock_index
623 return
624 }
625
626 + if {$revert} {
627 + # Save a copy of this patch for undoing reverts.
628 + set last_revert $wholepatch
629 + set last_revert_enc $enc
630 + }
631 +
632 $ui_diff conf -state normal
633 $ui_diff delete $s_lno $e_lno
634 $ui_diff conf -state disabled
@@ -653,7 +660,7 @@ proc apply_or_revert_hunk {x y revert} {
660
661 proc apply_or_revert_range_or_line {x y revert} {
662 global current_diff_path current_diff_header current_diff_side
656 - global ui_diff ui_index file_states
663 + global ui_diff ui_index file_states last_revert
664
665 set selected [$ui_diff tag nextrange sel 0.0]
666
@@ -852,5 +859,43 @@ proc apply_or_revert_range_or_line {x y revert} {
859 return
860 }
861
862 + if {$revert} {
863 + # Save a copy of this patch for undoing reverts.
864 + set last_revert $current_diff_header$wholepatch
865 + set last_revert_enc $enc
866 + }
867 +
868 + unlock_index
869 +}
870 +
871 +# Undo the last line/hunk reverted. When hunks and lines are reverted, a copy
872 +# of the diff applied is saved. Re-apply that diff to undo the revert.
873 +#
874 +# Right now, we only use a single variable to hold the copy, and not a
875 +# stack/deque for simplicity, so multiple undos are not possible. Maybe this
876 +# can be added if the need for something like this is felt in the future.
877 +proc undo_last_revert {} {
878 + global last_revert current_diff_path current_diff_header
879 + global last_revert_enc
880 +
881 + if {$last_revert eq {}} return
882 + if {![lock_index apply_hunk]} return
883 +
884 + set apply_cmd {apply --whitespace=nowarn}
885 + set failed_msg [mc "Failed to undo last revert."]
886 +
887 + if {[catch {
888 + set enc $last_revert_enc
889 + set p [eval git_write $apply_cmd]
890 + fconfigure $p -translation binary -encoding $enc
891 + puts -nonewline $p $last_revert
892 + close $p} err]} {
893 + error_popup "$failed_msg\n\n$err"
894 + unlock_index
895 + return
896 + }
897 +
898 + set last_revert {}
899 +
900 unlock_index
901 }