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 $USAGE
  22
  23 Blob ids and modes should be empty for missing files."
  24
  25 SUBDIRECTORY_OK=Yes
  26 . git-sh-setup
  27 cd_to_toplevel
  28 require_work_tree
  29
  30 if ! test "$#" -eq 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 [ "$2" ]; then
  42                 echo "Removing $4"
  43         else
  44                 # read-tree checked that index matches HEAD already,
  45                 # so we know we do not have this path tracked.
  46                 # there may be an unrelated working tree file here,
  47                 # which we should just leave unmolested.  Make sure
  48                 # we do not have it in the index, though.
  49                 exec git update-index --remove -- "$4"
  50         fi
  51         if test -f "$4"; then
  52                 rm -f -- "$4" &&
  53                 rmdir -p "$(expr "z$4" : 'z\(.*\)/')" 2>/dev/null || :
  54         fi &&
  55                 exec git update-index --remove -- "$4"
  56         ;;
  57
  58 #
  59 # Added in one.
  60 #
  61 ".$2.")
  62         # the other side did not add and we added so there is nothing
  63         # to be done, except making the path merged.
  64         exec git update-index --add --cacheinfo "$6" "$2" "$4"
  65         ;;
  66 "..$3")
  67         echo "Adding $4"
  68         if test -f "$4"
  69         then
  70                 echo "ERROR: untracked $4 is overwritten by the merge."
  71                 exit 1
  72         fi
  73         git update-index --add --cacheinfo "$7" "$3" "$4" &&
  74                 exec git checkout-index -u -f -- "$4"
  75         ;;
  76
  77 #
  78 # Added in both, identically (check for same permissions).
  79 #
  80 ".$3$2")
  81         if [ "$6" != "$7" ]; then
  82                 echo "ERROR: File $4 added identically in both branches,"
  83                 echo "ERROR: but permissions conflict $6->$7."
  84                 exit 1
  85         fi
  86         echo "Adding $4"
  87         git update-index --add --cacheinfo "$6" "$2" "$4" &&
  88                 exec git checkout-index -u -f -- "$4"
  89         ;;
  90
  91 #
  92 # Modified in both, but differently.
  93 #
  94 "$1$2$3" | ".$2$3")
  95
  96         case ",$6,$7," in
  97         *,120000,*)
  98                 echo "ERROR: $4: Not merging symbolic link changes."
  99                 exit 1
 100                 ;;
 101         *,160000,*)
 102                 echo "ERROR: $4: Not merging conflicting submodule changes."
 103                 exit 1
 104                 ;;
 105         esac
 106
 107         src2=`git-unpack-file $3`
 108         case "$1" in
 109         '')
 110                 echo "Added $4 in both, but differently."
 111                 # This extracts OUR file in $orig, and uses git apply to
 112                 # remove lines that are unique to ours.
 113                 orig=`git-unpack-file $2`
 114                 sz0=`wc -c <"$orig"`
 115                 diff -u -La/$orig -Lb/$orig $orig $src2 | git apply --no-add
 116                 sz1=`wc -c <"$orig"`
 117
 118                 # If we do not have enough common material, it is not
 119                 # worth trying two-file merge using common subsections.
 120                 expr "$sz0" \< "$sz1" \* 2 >/dev/null || : >$orig
 121                 ;;
 122         *)
 123                 echo "Auto-merging $4"
 124                 orig=`git-unpack-file $1`
 125                 ;;
 126         esac
 127
 128         # Be careful for funny filename such as "-L" in "$4", which
 129         # would confuse "merge" greatly.
 130         src1=`git-unpack-file $2`
 131         git merge-file "$src1" "$orig" "$src2"
 132         ret=$?
 133         msg=
 134         if [ $ret -ne 0 ]; then
 135                 msg='content conflict'
 136         fi
 137
 138         # Create the working tree file, using "our tree" version from the
 139         # index, and then store the result of the merge.
 140         git checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4" || exit 1
 141         rm -f -- "$orig" "$src1" "$src2"
 142
 143         if [ "$6" != "$7" ]; then
 144                 if [ -n "$msg" ]; then
 145                         msg="$msg, "
 146                 fi
 147                 msg="${msg}permissions conflict: $5->$6,$7"
 148                 ret=1
 149         fi
 150         if [ "$1" = '' ]; then
 151                 ret=1
 152         fi
 153
 154         if [ $ret -ne 0 ]; then
 155                 echo "ERROR: $msg in $4"
 156                 exit 1
 157         fi
 158         exec git update-index -- "$4"
 159         ;;
 160
 161 *)
 162         echo "ERROR: $4: Not handling case $1 -> $2 -> $3"
 163         ;;
 164 esac
 165 exit 1