Merge branch 'da/difftool'

* da/difftool:
  mergetool--lib: simplify API usage by removing more global variables
  Fix misspelled mergetool.keepBackup
  difftool/mergetool: refactor commands to use git-mergetool--lib
  mergetool: use $( ... ) instead of `backticks`
  bash completion: add git-difftool
  difftool: add support for a difftool.prompt config variable
  difftool: add various git-difftool tests
  difftool: move 'git-difftool' out of contrib
  difftool/mergetool: add diffuse as merge and diff tool
  difftool: add a -y shortcut for --no-prompt
  difftool: use perl built-ins when testing for msys
  difftool: remove the backup file feature
  difftool: remove merge options for opendiff, tkdiff, kdiff3 and xxdiff
  git-mergetool: add new merge tool TortoiseMerge
  git-mergetool/difftool: make (g)vimdiff workable under Windows
  doc/merge-config: list ecmerge as a built-in merge tool

1 files changed, 59 insertions, 0 deletions

diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
new file mode 100755
index 0000000..57e8e32
--- /dev/null
+++ b/git-difftool--helper.sh
@@ -0,0 +1,59 @@
+#!/bin/sh
+# git-difftool--helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
+# This script is typically launched by using the 'git difftool'
+# convenience command.
+#
+# Copyright (c) 2009 David Aguilar
+
+# Load common functions from git-mergetool--lib
+TOOL_MODE=diff
+. git-mergetool--lib
+
+# difftool.prompt controls the default prompt/no-prompt behavior
+# and is overridden with $GIT_DIFFTOOL*_PROMPT.
+should_prompt () {
+	prompt=$(git config --bool difftool.prompt || echo true)
+	if test "$prompt" = true; then
+		test -z "$GIT_DIFFTOOL_NO_PROMPT"
+	else
+		test -n "$GIT_DIFFTOOL_PROMPT"
+	fi
+}
+
+# Sets up shell variables and runs a merge tool
+launch_merge_tool () {
+	# Merged is the filename as it appears in the work tree
+	# Local is the contents of a/filename
+	# Remote is the contents of b/filename
+	# Custom merge tool commands might use $BASE so we provide it
+	MERGED="$1"
+	LOCAL="$2"
+	REMOTE="$3"
+	BASE="$1"
+
+	# $LOCAL and $REMOTE are temporary files so prompt
+	# the user with the real $MERGED name before launching $merge_tool.
+	if should_prompt; then
+		printf "\nViewing: '$MERGED'\n"
+		printf "Hit return to launch '%s': " "$merge_tool"
+		read ans
+	fi
+
+	# Run the appropriate merge tool command
+	run_merge_tool "$merge_tool"
+}
+
+# Allow GIT_DIFF_TOOL and GIT_MERGE_TOOL to provide default values
+test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
+test -n "$GIT_DIFF_TOOL" && merge_tool="$GIT_DIFF_TOOL"
+
+if test -z "$merge_tool"; then
+	merge_tool="$(get_merge_tool)" || exit
+fi
+
+# Launch the merge tool on each path provided by 'git diff'
+while test $# -gt 6
+do
+	launch_merge_tool "$1" "$2" "$5"
+	shift 7
+done