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 $USAGE
  22
  23 Blob ids and modes should be empty for missing files."
  24
  25 if ! test "$#" -eq 7
  26 then
  27         echo "$LONG_USAGE"
  28         exit 1
  29 fi
  30
  31 case "${1:-.}${2:-.}${3:-.}" in
  32 #
  33 # Deleted in both or deleted in one and unchanged in the other
  34 #
  35 "$1.." | "$1.$1" | "$1$1.")
  36         if [ "$2" ]; then
  37                 echo "Removing $4"
  38         else
  39                 # read-tree checked that index matches HEAD already,
  40                 # so we know we do not have this path tracked.
  41                 # there may be an unrelated working tree file here,
  42                 # which we should just leave unmolested.  Make sure
  43                 # we do not have it in the index, though.
  44                 exec git update-index --remove -- "$4"
  45         fi
  46         if test -f "$4"; then
  47                 rm -f -- "$4" &&
  48                 rmdir -p "$(expr "z$4" : 'z\(.*\)/')" 2>/dev/null || :
  49         fi &&
  50                 exec git update-index --remove -- "$4"
  51         ;;
  52
  53 #
  54 # Added in one.
  55 #
  56 ".$2.")
  57         # the other side did not add and we added so there is nothing
  58         # to be done, except making the path merged.
  59         exec git update-index --add --cacheinfo "$6" "$2" "$4"
  60         ;;
  61 "..$3")
  62         echo "Adding $4"
  63         if test -f "$4"
  64         then
  65                 echo "ERROR: untracked $4 is overwritten by the merge."
  66                 exit 1
  67         fi
  68         git update-index --add --cacheinfo "$7" "$3" "$4" &&
  69                 exec git checkout-index -u -f -- "$4"
  70         ;;
  71
  72 #
  73 # Added in both, identically (check for same permissions).
  74 #
  75 ".$3$2")
  76         if [ "$6" != "$7" ]; then
  77                 echo "ERROR: File $4 added identically in both branches,"
  78                 echo "ERROR: but permissions conflict $6->$7."
  79                 exit 1
  80         fi
  81         echo "Adding $4"
  82         git update-index --add --cacheinfo "$6" "$2" "$4" &&
  83                 exec git checkout-index -u -f -- "$4"
  84         ;;
  85
  86 #
  87 # Modified in both, but differently.
  88 #
  89 "$1$2$3" | ".$2$3")
  90
  91         case ",$6,$7," in
  92         *,120000,*)
  93                 echo "ERROR: $4: Not merging symbolic link changes."
  94                 exit 1
  95                 ;;
  96         *,160000,*)
  97                 echo "ERROR: $4: Not merging conflicting submodule changes."
  98                 exit 1
  99                 ;;
 100         esac
 101
 102         src2=`git-unpack-file $3`
 103         case "$1" in
 104         '')
 105                 echo "Added $4 in both, but differently."
 106                 # This extracts OUR file in $orig, and uses git apply to
 107                 # remove lines that are unique to ours.
 108                 orig=`git-unpack-file $2`
 109                 sz0=`wc -c <"$orig"`
 110                 diff -u -La/$orig -Lb/$orig $orig $src2 | git apply --no-add
 111                 sz1=`wc -c <"$orig"`
 112
 113                 # If we do not have enough common material, it is not
 114                 # worth trying two-file merge using common subsections.
 115                 expr "$sz0" \< "$sz1" \* 2 >/dev/null || : >$orig
 116                 ;;
 117         *)
 118                 echo "Auto-merging $4"
 119                 orig=`git-unpack-file $1`
 120                 ;;
 121         esac
 122
 123         # Be careful for funny filename such as "-L" in "$4", which
 124         # would confuse "merge" greatly.
 125         src1=`git-unpack-file $2`
 126         git merge-file "$src1" "$orig" "$src2"
 127         ret=$?
 128         msg=
 129         if [ $ret -ne 0 ]; then
 130                 msg='content conflict'
 131         fi
 132
 133         # Create the working tree file, using "our tree" version from the
 134         # index, and then store the result of the merge.
 135         git checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4"
 136         rm -f -- "$orig" "$src1" "$src2"
 137
 138         if [ "$6" != "$7" ]; then
 139                 if [ -n "$msg" ]; then
 140                         msg="$msg, "
 141                 fi
 142                 msg="${msg}permissions conflict: $5->$6,$7"
 143                 ret=1
 144         fi
 145         if [ "$1" = '' ]; then
 146                 ret=1
 147         fi
 148
 149         if [ $ret -ne 0 ]; then
 150                 echo "ERROR: $msg in $4"
 151                 exit 1
 152         fi
 153         exec git update-index -- "$4"
 154         ;;
 155
 156 *)
 157         echo "ERROR: $4: Not handling case $1 -> $2 -> $3"
 158         ;;
 159 esac
 160 exit 1