git-merge-one-file.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) Linus Torvalds, 2005
   4 #
   5 # This is the git per-file merge script, called with
   6 #
   7 #   $1 - original file SHA1 (or empty)
   8 #   $2 - file in branch1 SHA1 (or empty)
   9 #   $3 - file in branch2 SHA1 (or empty)
  10 #   $4 - pathname in repository
  11 #   $5 - original file mode (or empty)
  12 #   $6 - file in branch1 mode (or empty)
  13 #   $7 - file in branch2 mode (or empty)
  14 #
  15 # Handle some trivial cases.. The _really_ trivial cases have
  16 # been handled already by git read-tree, but that one doesn't
  17 # do any merges that might change the tree layout.
  18
  19 USAGE='<orig blob> <our blob> <their blob> <path>'
  20 USAGE="$USAGE <orig mode> <our mode> <their mode>"
  21 LONG_USAGE="usage: git merge-one-file $USAGE
  22
  23 Blob ids and modes should be empty for missing files."
  24
  25 SUBDIRECTORY_OK=Yes
  26 . git-sh-setup
  27 cd_to_toplevel
  28 require_work_tree
  29
  30 if test $# != 7
  31 then
  32         echo "$LONG_USAGE"
  33         exit 1
  34 fi
  35
  36 case "${1:-.}${2:-.}${3:-.}" in
  37 #
  38 # Deleted in both or deleted in one and unchanged in the other
  39 #
  40 "$1.." | "$1.$1" | "$1$1.")
  41         if { test -z "$6" && test "$5" != "$7"; } ||
  42            { test -z "$7" && test "$5" != "$6"; }
  43         then
  44                 echo "ERROR: File $4 deleted on one branch but had its" >&2
  45                 echo "ERROR: permissions changed on the other." >&2
  46                 exit 1
  47         fi
  48
  49         if test -n "$2"
  50         then
  51                 echo "Removing $4"
  52         else
  53                 # read-tree checked that index matches HEAD already,
  54                 # so we know we do not have this path tracked.
  55                 # there may be an unrelated working tree file here,
  56                 # which we should just leave unmolested.  Make sure
  57                 # we do not have it in the index, though.
  58                 exec git update-index --remove -- "$4"
  59         fi
  60         if test -f "$4"
  61         then
  62                 rm -f -- "$4" &&
  63                 rmdir -p "$(expr "z$4" : 'z\(.*\)/')" 2>/dev/null || :
  64         fi &&
  65                 exec git update-index --remove -- "$4"
  66         ;;
  67
  68 #
  69 # Added in one.
  70 #
  71 ".$2.")
  72         # the other side did not add and we added so there is nothing
  73         # to be done, except making the path merged.
  74         exec git update-index --add --cacheinfo "$6" "$2" "$4"
  75         ;;
  76 "..$3")
  77         echo "Adding $4"
  78         if test -f "$4"
  79         then
  80                 echo "ERROR: untracked $4 is overwritten by the merge." >&2
  81                 exit 1
  82         fi
  83         git update-index --add --cacheinfo "$7" "$3" "$4" &&
  84                 exec git checkout-index -u -f -- "$4"
  85         ;;
  86
  87 #
  88 # Added in both, identically (check for same permissions).
  89 #
  90 ".$3$2")
  91         if test "$6" != "$7"
  92         then
  93                 echo "ERROR: File $4 added identically in both branches," >&2
  94                 echo "ERROR: but permissions conflict $6->$7." >&2
  95                 exit 1
  96         fi
  97         echo "Adding $4"
  98         git update-index --add --cacheinfo "$6" "$2" "$4" &&
  99                 exec git checkout-index -u -f -- "$4"
 100         ;;
 101
 102 #
 103 # Modified in both, but differently.
 104 #
 105 "$1$2$3" | ".$2$3")
 106
 107         case ",$6,$7," in
 108         *,120000,*)
 109                 echo "ERROR: $4: Not merging symbolic link changes." >&2
 110                 exit 1
 111                 ;;
 112         *,160000,*)
 113                 echo "ERROR: $4: Not merging conflicting submodule changes." >&2
 114                 exit 1
 115                 ;;
 116         esac
 117
 118         src1=$(git unpack-file $2)
 119         src2=$(git unpack-file $3)
 120         case "$1" in
 121         '')
 122                 echo "Added $4 in both, but differently."
 123                 orig=$(git unpack-file $(git hash-object /dev/null))
 124                 ;;
 125         *)
 126                 echo "Auto-merging $4"
 127                 orig=$(git unpack-file $1)
 128                 ;;
 129         esac
 130
 131         git merge-file "$src1" "$orig" "$src2"
 132         ret=$?
 133         msg=
 134         if test $ret != 0 || test -z "$1"
 135         then
 136                 msg='content conflict'
 137                 ret=1
 138         fi
 139
 140         # Create the working tree file, using "our tree" version from the
 141         # index, and then store the result of the merge.
 142         git checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4" || exit 1
 143         rm -f -- "$orig" "$src1" "$src2"
 144
 145         if test "$6" != "$7"
 146         then
 147                 if test -n "$msg"
 148                 then
 149                         msg="$msg, "
 150                 fi
 151                 msg="${msg}permissions conflict: $5->$6,$7"
 152                 ret=1
 153         fi
 154
 155         if test $ret != 0
 156         then
 157                 echo "ERROR: $msg in $4" >&2
 158                 exit 1
 159         fi
 160         exec git update-index -- "$4"
 161         ;;
 162
 163 *)
 164         echo "ERROR: $4: Not handling case $1 -> $2 -> $3" >&2
 165         ;;
 166 esac
 167 exit 1