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 #   $7 - file in branch2 mode (or empty)
  14 #
  15 # Handle some trivial cases.. The _really_ trivial cases have
  16 # been handled already by git-read-tree, but that one doesn't
  17 # do any merges that might change the tree layout.
  18
  19 case "${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         fi
  27         if test -f "$4"; then
  28                 rm -f -- "$4" &&
  29                 rmdir -p "$(expr "$4" : '\(.*\)/')" 2>/dev/null || :
  30         fi &&
  31                 exec git-update-index --remove -- "$4"
  32         ;;
  33
  34 #
  35 # Added in one.
  36 #
  37 ".$2." | "..$3" )
  38         echo "Adding $4"
  39         git-update-index --add --cacheinfo "$6$7" "$2$3" "$4" &&
  40                 exec git-checkout-index -u -f -- "$4"
  41         ;;
  42
  43 #
  44 # Added in both, identically (check for same permissions).
  45 #
  46 ".$3$2")
  47         if [ "$6" != "$7" ]; then
  48                 echo "ERROR: File $4 added identically in both branches,"
  49                 echo "ERROR: but permissions conflict $6->$7."
  50                 exit 1
  51         fi
  52         echo "Adding $4"
  53         git-update-index --add --cacheinfo "$6" "$2" "$4" &&
  54                 exec git-checkout-index -u -f -- "$4"
  55         ;;
  56
  57 #
  58 # Modified in both, but differently.
  59 #
  60 "$1$2$3" | ".$2$3")
  61
  62         case ",$6,$7," in
  63         *,120000,*)
  64                 echo "ERROR: $4: Not merging symbolic link changes."
  65                 exit 1
  66                 ;;
  67         esac
  68
  69         src2=`git-unpack-file $3`
  70         case "$1" in
  71         '')
  72                 echo "Added $4 in both, but differently."
  73                 # This extracts OUR file in $orig, and uses git-apply to
  74                 # remove lines that are unique to ours.
  75                 orig=`git-unpack-file $2`
  76                 sz0=`wc -c <"$orig"`
  77                 diff -u -La/$orig -Lb/$orig $orig $src2 | git-apply --no-add
  78                 sz1=`wc -c <"$orig"`
  79
  80                 # If we do not have enough common material, it is not
  81                 # worth trying two-file merge using common subsections.
  82                 expr "$sz0" \< "$sz1" \* 2 >/dev/null || : >$orig
  83                 ;;
  84         *)
  85                 echo "Auto-merging $4."
  86                 orig=`git-unpack-file $1`
  87                 ;;
  88         esac
  89
  90         # Create the working tree file, with the correct permission bits.
  91         # we can not rely on the fact that our tree has the path, because
  92         # we allow the merge to be done in an unchecked-out working tree.
  93         rm -f "$4" &&
  94                 git-cat-file blob "$2" >"$4" &&
  95                 case "$6" in *7??) chmod +x "$4" ;; esac &&
  96                 merge "$4" "$orig" "$src2"
  97         ret=$?
  98         rm -f -- "$orig" "$src2"
  99
 100         if [ "$6" != "$7" ]; then
 101                 echo "ERROR: Permissions conflict: $5->$6,$7."
 102                 ret=1
 103         fi
 104         if [ "$1" = '' ]; then
 105                 ret=1
 106         fi
 107
 108         if [ $ret -ne 0 ]; then
 109                 echo "ERROR: Merge conflict in $4."
 110                 exit 1
 111         fi
 112         exec git-update-index -- "$4"
 113         ;;
 114
 115 *)
 116         echo "ERROR: $4: Not handling case $1 -> $2 -> $3"
 117         ;;
 118 esac
 119 exit 1