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 - orignal 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 verify_path() {
  20     file="$1"
  21     dir=`dirname "$file"` &&
  22     mkdir -p "$dir" &&
  23     rm -f -- "$file" &&
  24     : >"$file"
  25 }
  26
  27 case "${1:-.}${2:-.}${3:-.}" in
  28 #
  29 # Deleted in both or deleted in one and unchanged in the other
  30 #
  31 "$1.." | "$1.$1" | "$1$1.")
  32         if [ "$2" ]; then
  33                 echo "Removing $4"
  34         fi
  35         if test -f "$4"; then
  36                 rm -f -- "$4" &&
  37                 rmdir -p "$(expr "$4" : '\(.*\)/')" 2>/dev/null || :
  38         fi &&
  39                 exec git-update-index --remove -- "$4"
  40         ;;
  41
  42 #
  43 # Added in one.
  44 #
  45 ".$2." | "..$3" )
  46         echo "Adding $4"
  47         git-update-index --add --cacheinfo "$6$7" "$2$3" "$4" &&
  48                 exec git-checkout-index -u -f -- "$4"
  49         ;;
  50
  51 #
  52 # Added in both, identically (check for same permissions).
  53 #
  54 ".$3$2")
  55         if [ "$6" != "$7" ]; then
  56                 echo "ERROR: File $4 added identically in both branches,"
  57                 echo "ERROR: but permissions conflict $6->$7."
  58                 exit 1
  59         fi
  60         echo "Adding $4"
  61         git-update-index --add --cacheinfo "$6" "$2" "$4" &&
  62                 exec git-checkout-index -u -f -- "$4"
  63         ;;
  64
  65 #
  66 # Modified in both, but differently.
  67 #
  68 "$1$2$3" | ".$2$3")
  69
  70         case ",$6,$7," in
  71         *,120000,*)
  72                 echo "ERROR: $4: Not merging symbolic link changes."
  73                 exit 1
  74                 ;;
  75         esac
  76
  77         src2=`git-unpack-file $3`
  78         case "$1" in
  79         '')
  80                 echo "Added $4 in both, but differently."
  81                 # This extracts OUR file in $orig, and uses git-apply to
  82                 # remove lines that are unique to ours.
  83                 orig=`git-unpack-file $2`
  84                 sz0=`wc -c <"$orig"`
  85                 diff -u -La/$orig -Lb/$orig $orig $src2 | git-apply --no-add
  86                 sz1=`wc -c <"$orig"`
  87
  88                 # If we do not have enough common material, it is not
  89                 # worth trying two-file merge using common subsections.
  90                 expr "$sz0" \< "$sz1" \* 2 >/dev/null || : >$orig
  91                 ;;
  92         *)
  93                 echo "Auto-merging $4."
  94                 orig=`git-unpack-file $1`
  95                 ;;
  96         esac
  97
  98         # Create the working tree file, with the correct permission bits.
  99         # we can not rely on the fact that our tree has the path, because
 100         # we allow the merge to be done in an unchecked-out working tree.
 101         verify_path "$4" &&
 102                 git-cat-file blob "$2" >"$4" &&
 103                 case "$6" in *7??) chmod +x -- "$4" ;; esac &&
 104                 merge "$4" "$orig" "$src2"
 105         ret=$?
 106         rm -f -- "$orig" "$src2"
 107
 108         if [ "$6" != "$7" ]; then
 109                 echo "ERROR: Permissions conflict: $5->$6,$7."
 110                 ret=1
 111         fi
 112         if [ "$1" = '' ]; then
 113                 ret=1
 114         fi
 115
 116         if [ $ret -ne 0 ]; then
 117                 echo "ERROR: Merge conflict in $4."
 118                 exit 1
 119         fi
 120         exec git-update-index -- "$4"
 121         ;;
 122
 123 *)
 124         echo "ERROR: $4: Not handling case $1 -> $2 -> $3"
 125         ;;
 126 esac
 127 exit 1