1 files changed, 71 insertions, 0 deletions
diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
new file mode 100755
index 0000000000..524f5ea8ab
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+++ b/git-difftool--helper.sh
@@ -0,0 +1,71 @@
+#!/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, 2010 David Aguilar
+
+TOOL_MODE=diff
+. git-mergetool--lib
+
+# difftool.prompt controls the default prompt/no-prompt behavior
+# and is overridden with $GIT_DIFFTOOL*_PROMPT.
+should_prompt () {
+	prompt_merge=$(git config --bool mergetool.prompt || echo true)
+	prompt=$(git config --bool difftool.prompt || echo $prompt_merge)
+	if test "$prompt" = true; then
+		test -z "$GIT_DIFFTOOL_NO_PROMPT"
+	else
+		test -n "$GIT_DIFFTOOL_PROMPT"
+	fi
+}
+
+# Indicates that --extcmd=... was specified
+use_ext_cmd () {
+	test -n "$GIT_DIFFTOOL_EXTCMD"
+}
+
+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"
+		if use_ext_cmd; then
+			printf "Hit return to launch '%s': " \
+				"$GIT_DIFFTOOL_EXTCMD"
+		else
+			printf "Hit return to launch '%s': " "$merge_tool"
+		fi
+		read ans
+	fi
+
+	if use_ext_cmd; then
+		eval $GIT_DIFFTOOL_EXTCMD '"$LOCAL"' '"$REMOTE"'
+	else
+		run_merge_tool "$merge_tool"
+	fi
+}
+
+if ! use_ext_cmd; then
+	if test -n "$GIT_DIFF_TOOL"; then
+		merge_tool="$GIT_DIFF_TOOL"
+	else
+		merge_tool="$(get_merge_tool)" || exit
+	fi
+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