Merge branch 'kb/p4merge'

Adjust the order mergetools feeds the files to the p4merge backend
to match the p4 convention.

* kb/p4merge:
merge-one-file: force content conflict for "both sides added" case
git-merge-one-file: send "ERROR:" messages to stderr
git-merge-one-file: style cleanup
merge-one-file: remove stale comment
mergetools/p4merge: create a base if none available
mergetools/p4merge: swap LOCAL and REMOTE

diff --combined git-merge-one-file.sh
index 3373c040d4aae221386fac5ec2cd9a29344c1840,7e82facf919ad720075690ed51bedf6ccf037774..07dfeb8df4bf910c5c79fb4c3dd3345ba4719da0
--- 1/git-merge-one-file.sh
--- 2/git-merge-one-file.sh
+++ b/git-merge-one-file.sh
@@@ -18,7 -18,7 +18,7 @@@
  
  USAGE='<orig blob> <our blob> <their blob> <path>'
  USAGE="$USAGE <orig mode> <our mode> <their mode>"
 -LONG_USAGE="Usage: git merge-one-file $USAGE
 +LONG_USAGE="usage: git merge-one-file $USAGE
  
  Blob ids and modes should be empty for missing files."
  
@@@ -27,7 -27,7 +27,7 @@@ SUBDIRECTORY_OK=Ye
  cd_to_toplevel
  require_work_tree
  
- if ! test "$#" -eq 7
+ if test $# != 7
  then
        echo "$LONG_USAGE"
        exit 1
@@@ -38,7 -38,8 +38,8 @@@ case "${1:-.}${2:-.}${3:-.}" i
  # Deleted in both or deleted in one and unchanged in the other
  #
  "$1.." | "$1.$1" | "$1$1.")
-       if [ "$2" ]; then
+       if test -n "$2"
+       then
                echo "Removing $4"
        else
                # read-tree checked that index matches HEAD already,
@@@ -48,7 -49,8 +49,8 @@@
                # we do not have it in the index, though.
                exec git update-index --remove -- "$4"
        fi
-       if test -f "$4"; then
+       if test -f "$4"
+       then
                rm -f -- "$4" &&
                rmdir -p "$(expr "z$4" : 'z\(.*\)/')" 2>/dev/null || :
        fi &&
@@@ -67,7 -69,7 +69,7 @@@
        echo "Adding $4"
        if test -f "$4"
        then
-               echo "ERROR: untracked $4 is overwritten by the merge."
+               echo "ERROR: untracked $4 is overwritten by the merge." >&2
                exit 1
        fi
        git update-index --add --cacheinfo "$7" "$3" "$4" &&
@@@ -78,9 -80,10 +80,10 @@@
  # Added in both, identically (check for same permissions).
  #
  ".$3$2")
-       if [ "$6" != "$7" ]; then
-               echo "ERROR: File $4 added identically in both branches,"
-               echo "ERROR: but permissions conflict $6->$7."
+       if test "$6" != "$7"
+       then
+               echo "ERROR: File $4 added identically in both branches," >&2
+               echo "ERROR: but permissions conflict $6->$7." >&2
                exit 1
        fi
        echo "Adding $4"
@@@ -95,44 -98,36 +98,36 @@@
  
        case ",$6,$7," in
        *,120000,*)
-               echo "ERROR: $4: Not merging symbolic link changes."
+               echo "ERROR: $4: Not merging symbolic link changes." >&2
                exit 1
                ;;
        *,160000,*)
-               echo "ERROR: $4: Not merging conflicting submodule changes."
+               echo "ERROR: $4: Not merging conflicting submodule changes." >&2
                exit 1
                ;;
        esac
  
-       src2=`git-unpack-file $3`
+       src1=$(git-unpack-file $2)
+       src2=$(git-unpack-file $3)
        case "$1" in
        '')
                echo "Added $4 in both, but differently."
-               # This extracts OUR file in $orig, and uses git apply to
-               # remove lines that are unique to ours.
-               orig=`git-unpack-file $2`
-               sz0=`wc -c <"$orig"`
-               @@DIFF@@ -u -La/$orig -Lb/$orig $orig $src2 | git apply --no-add
-               sz1=`wc -c <"$orig"`
- 
-               # If we do not have enough common material, it is not
-               # worth trying two-file merge using common subsections.
-               expr $sz0 \< $sz1 \* 2 >/dev/null || : >$orig
+               orig=$(git-unpack-file $2)
+               create_virtual_base "$orig" "$src2"
                ;;
        *)
                echo "Auto-merging $4"
-               orig=`git-unpack-file $1`
+               orig=$(git-unpack-file $1)
                ;;
        esac
  
-       # Be careful for funny filename such as "-L" in "$4", which
-       # would confuse "merge" greatly.
-       src1=`git-unpack-file $2`
        git merge-file "$src1" "$orig" "$src2"
        ret=$?
        msg=
-       if [ $ret -ne 0 ]; then
+       if test $ret != 0 || test -z "$1"
+       then
                msg='content conflict'
+               ret=1
        fi
  
        # Create the working tree file, using "our tree" version from the
@@@ -140,26 -135,26 +135,26 @@@
        git checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4" || exit 1
        rm -f -- "$orig" "$src1" "$src2"
  
-       if [ "$6" != "$7" ]; then
-               if [ -n "$msg" ]; then
+       if test "$6" != "$7"
+       then
+               if test -n "$msg"
+               then
                        msg="$msg, "
                fi
                msg="${msg}permissions conflict: $5->$6,$7"
                ret=1
        fi
-       if [ "$1" = '' ]; then
-               ret=1
-       fi
  
-       if [ $ret -ne 0 ]; then
-               echo "ERROR: $msg in $4"
+       if test $ret != 0
+       then
+               echo "ERROR: $msg in $4" >&2
                exit 1
        fi
        exec git update-index -- "$4"
        ;;
  
  *)
-       echo "ERROR: $4: Not handling case $1 -> $2 -> $3"
+       echo "ERROR: $4: Not handling case $1 -> $2 -> $3" >&2
        ;;
  esac
  exit 1

diff --combined git-sh-setup.sh
index 9cfbe7f1435e073eeb39ab2190eda2d2dda300a5,349a5d44e877105db08b895d9c93f303168c4cd8..2f7835941ecaa48be17b6dd64e64fb0df3db37e2
--- 1/git-sh-setup.sh
--- 2/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@@ -84,14 -84,14 +84,14 @@@ if test -n "$OPTIONS_SPEC"; the
  else
        dashless=$(basename "$0" | sed -e 's/-/ /')
        usage() {
 -              die "Usage: $dashless $USAGE"
 +              die "usage: $dashless $USAGE"
        }
  
        if [ -z "$LONG_USAGE" ]
        then
 -              LONG_USAGE="Usage: $dashless $USAGE"
 +              LONG_USAGE="usage: $dashless $USAGE"
        else
 -              LONG_USAGE="Usage: $dashless $USAGE
 +              LONG_USAGE="usage: $dashless $USAGE
  
  $LONG_USAGE"
        fi
@@@ -249,6 -249,18 +249,18 @@@ clear_local_git_env() 
        unset $(git rev-parse --local-env-vars)
  }
  
+ # Generate a virtual base file for a two-file merge. Uses git apply to
+ # remove lines from $1 that are not in $2, leaving only common lines.
+ create_virtual_base() {
+       sz0=$(wc -c <"$1")
+       @@DIFF@@ -u -La/"$1" -Lb/"$1" "$1" "$2" | git apply --no-add
+       sz1=$(wc -c <"$1")
+ 
+       # If we do not have enough common material, it is not
+       # worth trying two-file merge using common subsections.
+       expr $sz0 \< $sz1 \* 2 >/dev/null || : >"$1"
+ }
+ 
  
  # Platform specific tweaks to work around some commands
  case $(uname -s) in