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