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         if [ "$1" = "755" ]; then
  57                 _pmxmc=+
  58         else
  59                 _pmxmc=-
  60         fi
  61 }
  62
  63 # Set ways[] to the symbolic names of the particular ways
  64 load_unescaped_sym_ways()
  65 {
  66         if [ "$_CG_MERGING_LOCAL" ]; then
  67                 ways=("original" "local" "target")
  68         else
  69                 ways=("merge base" "$_git_head" "$(cat "$_git/cg-merge-state/merging-sym")")
  70         fi
  71 }
  72 load_sym_ways()
  73 {
  74         load_unescaped_sym_ways
  75         ways[0]="${ways[0]// //}"
  76         ways=("${ways[@]//\//~}")
  77 }
  78
  79
  80 case "${id0:-.}${id1:-.}${id2:-.}" in
  81 #
  82 # Deleted in both or deleted in one and unchanged in the other
  83 #
  84 "$id0.." | "$id0.$id0" | "$id0$id0.")
  85         #echo "Removing $file"
  86         if test -f "$file"; then
  87                 rm -f -- "$file"
  88         fi &&
  89                 exec git-update-index --remove -- "$file"
  90         ;;
  91
  92 #
  93 # Deleted in one and changed in the other
  94 #
  95 "$id0$id1." | "$id0.$id2")
  96         #echo "Removing $file"
  97         filev="$file"
  98         load_sym_ways
  99         if [ "$id1" ]; then
 100                 num=1; mode="$mode1"; id="$id1"
 101         else
 102                 num=2; mode="$mode2"; id="$id2"
 103         fi
 104         while [ -e "$filev~${ways[0]}" ] || [ -e "$filev~${ways[$num]}" ]; do
 105                 filev="$filev~"
 106         done
 107         error "File $file removed in one branch but modified in the other!"
 108         error "The original version saved as '$filev~${ways[0]}', the modified one as '$filev~${ways[$num]}'."
 109         git-update-index --add --cacheinfo "$mode0" "$id0" "$file" &&
 110                 git-checkout-index -u -f -- "$file" &&
 111                 mv "$file" "$filev~${ways[0]}" ||
 112                 error "Cannot create '$filev~${ways[0]}'"
 113         git-update-index --add --cacheinfo "$mode" "$id" "$file" &&
 114                 git-checkout-index -u -f -- "$file" &&
 115                 mv "$file" "$filev~${ways[$num]}" ||
 116                 error "Cannot create '$filev~${ways[$num]}'"
 117         git-update-index --force-remove "$file"
 118         ;;
 119 #
 120 # Added in one.
 121 #
 122 ".$id1." | "..$id2" )
 123         #echo "Adding $file"
 124         git-update-index --add --cacheinfo "$mode1$mode2" "$id1$id2" "$file" &&
 125                 exec git-checkout-index -u -f -- "$file"
 126         ;;
 127
 128 #
 129 # Added same in both (check for same permissions).
 130 #
 131 ".$id2$id1")
 132         #echo "Adding $file"
 133         git-update-index --add --cacheinfo "$mode1" "$id1" "$file" &&
 134                 git-checkout-index -u -f -- "$file"
 135         ret=$?
 136         if [ "$mode1" != "$mode2" ]; then
 137                 pmxmc "$mode2"; chmod ${_pmxmc}x "$file"
 138                 error "$file: added in both branches, permissions conflict $mode1->$mode2 (defaulting to $mode2)"
 139                 exit 1
 140         fi
 141         exit $ret
 142         ;;
 143
 144 #
 145 # Added in both (different in each).
 146 #
 147 ".$id1$id2")
 148         #echo "Adding $file"
 149         filev="$file"
 150         load_sym_ways
 151         while [ -e "$filev~${ways[1]}" ] || [ -e "$filev~${ways[2]}" ]; do
 152                 filev="$filev~"
 153         done
 154         error "File $file added in both branches, but different in each!"
 155         error "Conflicting versions saved as '$filev~${ways[1]}' and '$filev~${ways[2]}'."
 156         git-update-index --add --cacheinfo "$mode1" "$id1" "$file" &&
 157                 git-checkout-index -u -f -- "$file" &&
 158                 mv "$file" "$filev~${ways[1]}" ||
 159                 error "Cannot create '$filev~${ways[1]}'"
 160         git-update-index --add --cacheinfo "$mode2" "$id2" "$file" &&
 161                 git-checkout-index -u -f -- "$file" &&
 162                 mv "$file" "$filev~${ways[2]}" ||
 163                 error "Cannot create '$filev~${ways[2]}'"
 164         exit 1
 165         ;;
 166
 167 #
 168 # Modified in both, but differently.
 169 #
 170 "$id0$id1$id2")
 171         echo "... Auto-merging $file"
 172         orig=$(git-unpack-file $id0)
 173         src2=$(git-unpack-file $id2)
 174         merged=$(mktemp .mergeresult-XXXXXX)
 175
 176         load_unescaped_sym_ways
 177         # We reset the index to the first branch, making
 178         # git-diff-file useful
 179         git-update-index --add --cacheinfo "$mode1" "$id1" "$file"
 180                 git-checkout-index -u -f -- "$file" &&
 181                 { diff3 -m -E -L "${ways[1]}" -L "${ways[0]}" -L "${ways[2]}" "$file" "$orig" "$src2" >"$merged"; }
 182         ret=$?
 183         rm -f -- "$orig" "$src2"
 184         cat "$merged" >"$file"
 185         rm "$merged"
 186
 187         if [ "$mode1" != "$mode2" ]; then
 188                 if [ "$mode0" = "$mode1" ]; then
 189                         moded="$mode2"
 190                 else
 191                         moded="$mode1"
 192                 fi
 193                 pmxmc "$moded"; chmod ${_pmxmc}x "$file"
 194                 error "Permissions conflict: $mode0->$mode1,$mode2 (defaulting to $moded)"
 195                 ret=1
 196         fi
 197
 198         if [ $ret -ne 0 ]; then
 199                 echo "    CONFLICTS during merge." >&2
 200                 exit 1
 201         fi
 202         exec git-update-index -- "$file"
 203         ;;
 204
 205 *)
 206         error "$file: Not handling case: ${id0:-empty} -> ${id1:-empty} -> ${id2:-empty} (this would be a Cogito bug, please report it)"
 207         ;;
 208 esac
 209 exit 1