cg-Xmergefile

   1 #!/usr/bin/env bash
   2 #
   3 # Merge two revisions of a file
   4 # Copyright (c) Linus Torvalds, 2005
   5 # Copyright (c) Petr Baudis, 2005, 2006
   6 #
   7 # This is the git per-file merge script, called with
   8 #
   9 #   $1 - original file SHA1 (or empty)
  10 #   $2 - file in branch1 SHA1 (or empty)
  11 #   $3 - file in branch2 SHA1 (or empty)
  12 #   $4 - pathname in repository
  13 #   $5 - original file mode (or empty)
  14 #   $6 - file in branch1 mode (or empty)
  15 #   $7 - file in branch2 mode (or empty)
  16 #
  17 # We are designed to merge $3 _to_ $2, so we will give it
  18 # a preference.
  19 #
  20 # FIXME: Make at least some effort to protect against checking in
  21 # the conflicts.
  22 #
  23 # FIXME: What if a symlink replaces a regular file? What if symlinks conflict?
  24 # What about directory-regularfile conflicts?
  25 #
  26 # ENVIRONMENT
  27 # -----------
  28 # _CG_MERGING_LOCAL::
  29 #       If set, we are merging local changes, not "real" three trees.
  30
  31 . "${COGITO_LIB}"cg-Xlib || exit 1
  32
  33 id0="${ARGS[0]}"
  34 id1="${ARGS[1]}"
  35 id2="${ARGS[2]}"
  36 file="${ARGS[3]}"
  37 mode0="${ARGS[4]}"
  38 mode1="${ARGS[5]}"
  39 mode2="${ARGS[6]}"
  40
  41 error()
  42 {
  43         echo "MERGE ERROR: $@" >&2
  44         return 1
  45 }
  46
  47 warning()
  48 {
  49         echo "MERGE WARNING: $@" >&2
  50 }
  51
  52 # Returns stuff in $_pmxmc
  53 # PlusMinus+XModeChar ;-)
  54 pmxmc()
  55 {
  56         case "$1" in
  57         *755)
  58                 _pmxmc=+;;
  59         *)
  60                 _pmxmc=-;;
  61         esac
  62 }
  63
  64 # Set ways[] to the symbolic names of the particular ways
  65 load_unescaped_sym_ways()
  66 {
  67         if [ "$_CG_MERGING_LOCAL" ]; then
  68                 ways=("original" "local" "target")
  69         else
  70                 ways=("merge base" "$_git_head" "$(cat "$_git/cg-merge-state/merging-sym")")
  71         fi
  72 }
  73 load_sym_ways()
  74 {
  75         load_unescaped_sym_ways
  76         ways[0]="${ways[0]// //}"
  77         ways=("${ways[@]//\//~}")
  78 }
  79
  80
  81 case "${id0:-.}${id1:-.}${id2:-.}" in
  82 #
  83 # Deleted in both or deleted in one and unchanged in the other
  84 #
  85 "$id0.." | "$id0.$id0" | "$id0$id0.")
  86         #echo "Removing $file"
  87         if test -f "$file"; then
  88                 rm -f -- "$file"
  89         fi &&
  90                 exec git-update-index --remove -- "$file"
  91         ;;
  92
  93 #
  94 # Deleted in one and changed in the other
  95 #
  96 "$id0$id1." | "$id0.$id2")
  97         #echo "Removing $file"
  98         filev="$file"
  99         load_sym_ways
 100         if [ "$id1" ]; then
 101                 num=1; mode="$mode1"; id="$id1"
 102         else
 103                 num=2; mode="$mode2"; id="$id2"
 104         fi
 105         while [ -e "$filev~${ways[0]}" ] || [ -e "$filev~${ways[$num]}" ]; do
 106                 filev="$filev~"
 107         done
 108         error "File $file removed in one branch but modified in the other!"
 109         error "The original version saved as '$filev~${ways[0]}', the modified one as '$filev~${ways[$num]}'."
 110         git-update-index --add --cacheinfo "$mode0" "$id0" "$file" &&
 111                 git-checkout-index -u -f -- "$file" &&
 112                 mv "$file" "$filev~${ways[0]}" ||
 113                 error "Cannot create '$filev~${ways[0]}'"
 114         git-update-index --add --cacheinfo "$mode" "$id" "$file" &&
 115                 git-checkout-index -u -f -- "$file" &&
 116                 mv "$file" "$filev~${ways[$num]}" ||
 117                 error "Cannot create '$filev~${ways[$num]}'"
 118         git-update-index --force-remove "$file"
 119         ;;
 120 #
 121 # Added in one.
 122 #
 123 ".$id1." | "..$id2" )
 124         #echo "Adding $file"
 125         git-update-index --add --cacheinfo "$mode1$mode2" "$id1$id2" "$file" &&
 126                 exec git-checkout-index -u -f -- "$file"
 127         ;;
 128
 129 #
 130 # Added same in both (check for same permissions).
 131 #
 132 ".$id2$id1")
 133         #echo "Adding $file"
 134         git-update-index --add --cacheinfo "$mode1" "$id1" "$file" &&
 135                 git-checkout-index -u -f -- "$file"
 136         ret=$?
 137         if [ "$mode1" != "$mode2" ]; then
 138                 pmxmc "$mode2"; chmod ${_pmxmc}x "$file"
 139                 error "$file: added in both branches, permissions conflict $mode1->$mode2 (defaulting to $mode2)"
 140                 exit 1
 141         fi
 142         exit $ret
 143         ;;
 144
 145 #
 146 # Added in both (different in each).
 147 #
 148 ".$id1$id2")
 149         #echo "Adding $file"
 150         filev="$file"
 151         load_sym_ways
 152         while [ -e "$filev~${ways[1]}" ] || [ -e "$filev~${ways[2]}" ]; do
 153                 filev="$filev~"
 154         done
 155         error "File $file added in both branches, but different in each!"
 156         error "Conflicting versions saved as '$filev~${ways[1]}' and '$filev~${ways[2]}'."
 157         git-update-index --add --cacheinfo "$mode1" "$id1" "$file" &&
 158                 git-checkout-index -u -f -- "$file" &&
 159                 mv "$file" "$filev~${ways[1]}" ||
 160                 error "Cannot create '$filev~${ways[1]}'"
 161         git-update-index --add --cacheinfo "$mode2" "$id2" "$file" &&
 162                 git-checkout-index -u -f -- "$file" &&
 163                 mv "$file" "$filev~${ways[2]}" ||
 164                 error "Cannot create '$filev~${ways[2]}'"
 165         exit 1
 166         ;;
 167
 168 #
 169 # Modified in both, but differently.
 170 #
 171 "$id0$id1$id2")
 172         echo "... Auto-merging $file"
 173         orig=$(git-unpack-file $id0)
 174         src2=$(git-unpack-file $id2)
 175         merged=$(mktemp .mergeresult-XXXXXX)
 176
 177         load_unescaped_sym_ways
 178         # We reset the index to the first branch, making
 179         # git-diff-file useful
 180         git-update-index --add --cacheinfo "$mode1" "$id1" "$file"
 181                 git-checkout-index -u -f -- "$file" &&
 182                 { diff3 -m -E -L "${ways[1]}" -L "${ways[0]}" -L "${ways[2]}" "$file" "$orig" "$src2" >"$merged"; }
 183         ret=$?
 184         rm -f -- "$orig" "$src2"
 185         cat "$merged" >"$file"
 186         rm "$merged"
 187
 188         if [ "$mode1" != "$mode2" ]; then
 189                 if [ "$mode0" = "$mode1" ]; then
 190                         moded="$mode2"
 191                 else
 192                         moded="$mode1"
 193                 fi
 194                 pmxmc "$moded"; chmod ${_pmxmc}x "$file"
 195                 error "Permissions conflict: $mode0->$mode1,$mode2 (defaulting to $moded)"
 196                 ret=1
 197         fi
 198
 199         if [ $ret -ne 0 ]; then
 200                 echo "    CONFLICTS during merge." >&2
 201                 exit 1
 202         fi
 203         exec git-update-index -- "$file"
 204         ;;
 205
 206 *)
 207         error "$file: Not handling case: ${id0:-empty} -> ${id1:-empty} -> ${id2:-empty} (this would be a Cogito bug, please report it)"
 208         ;;
 209 esac
 210 exit 1