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 #   $7 - file in branch2 mode (or empty)
  14 #
  15 # Handle some trivial cases.. The _really_ trivial cases have
  16 # been handled already by git-read-tree, but that one doesn't
  17 # do any merges that might change the tree layout.
  18
  19 case "${1:-.}${2:-.}${3:-.}" in
  20 #
  21 # Deleted in both or deleted in one and unchanged in the other
  22 #
  23 "$1.." | "$1.$1" | "$1$1.")
  24         if [ "$2" ]; then
  25                 echo "Removing $4"
  26         else
  27                 # read-tree checked that index matches HEAD already,
  28                 # so we know we do not have this path tracked.
  29                 # there may be an unrelated working tree file here,
  30                 # which we should just leave unmolested.
  31                 exit 0
  32         fi
  33         if test -f "$4"; then
  34                 rm -f -- "$4" &&
  35                 rmdir -p "$(expr "z$4" : 'z\(.*\)/')" 2>/dev/null || :
  36         fi &&
  37                 exec git-update-index --remove -- "$4"
  38         ;;
  39
  40 #
  41 # Added in one.
  42 #
  43 ".$2.")
  44         # the other side did not add and we added so there is nothing
  45         # to be done.
  46         ;;
  47 "..$3")
  48         echo "Adding $4"
  49         test -f "$4" || {
  50                 echo "ERROR: untracked $4 is overwritten by the merge."
  51                 exit 1
  52         }
  53         git-update-index --add --cacheinfo "$6$7" "$2$3" "$4" &&
  54                 exec git-checkout-index -u -f -- "$4"
  55         ;;
  56
  57 #
  58 # Added in both, identically (check for same permissions).
  59 #
  60 ".$3$2")
  61         if [ "$6" != "$7" ]; then
  62                 echo "ERROR: File $4 added identically in both branches,"
  63                 echo "ERROR: but permissions conflict $6->$7."
  64                 exit 1
  65         fi
  66         echo "Adding $4"
  67         git-update-index --add --cacheinfo "$6" "$2" "$4" &&
  68                 exec git-checkout-index -u -f -- "$4"
  69         ;;
  70
  71 #
  72 # Modified in both, but differently.
  73 #
  74 "$1$2$3" | ".$2$3")
  75
  76         case ",$6,$7," in
  77         *,120000,*)
  78                 echo "ERROR: $4: Not merging symbolic link changes."
  79                 exit 1
  80                 ;;
  81         esac
  82
  83         src2=`git-unpack-file $3`
  84         case "$1" in
  85         '')
  86                 echo "Added $4 in both, but differently."
  87                 # This extracts OUR file in $orig, and uses git-apply to
  88                 # remove lines that are unique to ours.
  89                 orig=`git-unpack-file $2`
  90                 sz0=`wc -c <"$orig"`
  91                 diff -u -La/$orig -Lb/$orig $orig $src2 | git-apply --no-add
  92                 sz1=`wc -c <"$orig"`
  93
  94                 # If we do not have enough common material, it is not
  95                 # worth trying two-file merge using common subsections.
  96                 expr "$sz0" \< "$sz1" \* 2 >/dev/null || : >$orig
  97                 ;;
  98         *)
  99                 echo "Auto-merging $4"
 100                 orig=`git-unpack-file $1`
 101                 ;;
 102         esac
 103
 104         # Be careful for funny filename such as "-L" in "$4", which
 105         # would confuse "merge" greatly.
 106         src1=`git-unpack-file $2`
 107         git-merge-file "$src1" "$orig" "$src2"
 108         ret=$?
 109
 110         # Create the working tree file, using "our tree" version from the
 111         # index, and then store the result of the merge.
 112         git-checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4"
 113         rm -f -- "$orig" "$src1" "$src2"
 114
 115         if [ "$6" != "$7" ]; then
 116                 echo "ERROR: Permissions conflict: $5->$6,$7."
 117                 ret=1
 118         fi
 119         if [ "$1" = '' ]; then
 120                 ret=1
 121         fi
 122
 123         if [ $ret -ne 0 ]; then
 124                 echo "ERROR: Merge conflict in $4"
 125                 exit 1
 126         fi
 127         exec git-update-index -- "$4"
 128         ;;
 129
 130 *)
 131         echo "ERROR: $4: Not handling case $1 -> $2 -> $3"
 132         ;;
 133 esac
 134 exit 1