git-reset.sh

   1 #!/bin/sh
   2 . git-sh-setup
   3
   4 usage () {
   5         die 'Usage: git reset [--mixed | --soft | --hard]  [<commit-ish>]'
   6 }
   7
   8 tmp=/var/tmp/reset.$$
   9 trap 'rm -f $tmp-*' 0 1 2 3 15
  10
  11 reset_type=--mixed
  12 case "$1" in
  13 --mixed | --soft | --hard)
  14         reset_type="$1"
  15         shift
  16         ;;
  17 -*)
  18         usage ;;
  19 esac
  20
  21 rev=$(git-rev-parse --verify --default HEAD "$@") || exit
  22 rev=$(git-rev-parse --verify $rev^0) || exit
  23
  24 # We need to remember the set of paths that _could_ be left
  25 # behind before a hard reset, so that we can remove them.
  26 if test "$reset_type" = "--hard"
  27 then
  28         {
  29                 git-ls-files --stage -z
  30                 git-rev-parse --verify HEAD 2>/dev/null &&
  31                 git-ls-tree -r -z HEAD
  32         } | perl -e '
  33             use strict;
  34             my %seen;
  35             $/ = "\0";
  36             while (<>) {
  37                 chomp;
  38                 my ($info, $path) = split(/\t/, $_);
  39                 next if ($info =~ / tree /);
  40                 if (!$seen{$path}) {
  41                         $seen{$path} = 1;
  42                         print "$path\0";
  43                 }
  44             }
  45         ' >$tmp-exists
  46 fi
  47
  48 # Soft reset does not touch the index file nor the working tree
  49 # at all, but requires them in a good order.  Other resets reset
  50 # the index file to the tree object we are switching to.
  51 if test "$reset_type" = "--soft"
  52 then
  53         if test -f "$GIT_DIR/MERGE_HEAD" ||
  54            test "" != "$(git-ls-files --unmerged)"
  55         then
  56                 die "Cannot do a soft reset in the middle of a merge."
  57         fi
  58 else
  59         git-read-tree --reset "$rev" || exit
  60 fi
  61
  62 # Any resets update HEAD to the head being switched to.
  63 if orig=$(git-rev-parse --verify HEAD 2>/dev/null)
  64 then
  65         echo "$orig" >"$GIT_DIR/ORIG_HEAD"
  66 else
  67         rm -f "$GIT_DIR/ORIG_HEAD"
  68 fi
  69 git-update-ref HEAD "$rev"
  70
  71 case "$reset_type" in
  72 --hard )
  73         # Hard reset matches the working tree to that of the tree
  74         # being switched to.
  75         git-checkout-index -f -u -q -a
  76         git-ls-files --cached -z |
  77         perl -e '
  78                 use strict;
  79                 my (%keep, $fh);
  80                 $/ = "\0";
  81                 while (<STDIN>) {
  82                         chomp;
  83                         $keep{$_} = 1;
  84                 }
  85                 open $fh, "<", $ARGV[0]
  86                         or die "cannot open $ARGV[0]";
  87                 while (<$fh>) {
  88                         chomp;
  89                         if (! exists $keep{$_}) {
  90                                 # it is ok if this fails -- it may already
  91                                 # have been culled by checkout-index.
  92                                 unlink $_;
  93                         }
  94                 }
  95         ' $tmp-exists
  96         ;;
  97 --soft )
  98         ;; # Nothing else to do
  99 --mixed )
 100         # Report what has not been updated.
 101         git-update-index --refresh
 102         ;;
 103 esac
 104
 105 rm -f "$GIT_DIR/MERGE_HEAD"