1 files changed, 72 insertions, 12 deletions

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index 14b039de65..9a8b97a2ab 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -100,7 +100,7 @@ check_unchanged () {
 		while true
 		do
 			echo "$MERGED seems unchanged."
-			printf "Was the merge successful? [y/n] "
+			printf "Was the merge successful [y/n]? "
 			read answer || return 1
 			case "$answer" in
 			y*|Y*) return 0 ;;
@@ -125,16 +125,7 @@ setup_user_tool () {
 	}
 
 	merge_cmd () {
-		trust_exit_code=$(git config --bool \
-			"mergetool.$1.trustExitCode" || echo false)
-		if test "$trust_exit_code" = "false"
-		then
-			touch "$BACKUP"
-			( eval $merge_tool_cmd )
-			check_unchanged
-		else
-			( eval $merge_tool_cmd )
-		fi
+		( eval $merge_tool_cmd )
 	}
 }
 
@@ -162,6 +153,28 @@ setup_tool () {
 		echo "$1"
 	}
 
+	# Most tools' exit codes cannot be trusted, so By default we ignore
+	# their exit code and check the merged file's modification time in
+	# check_unchanged() to determine whether or not the merge was
+	# successful.  The return value from run_merge_cmd, by default, is
+	# determined by check_unchanged().
+	#
+	# When a tool's exit code can be trusted then the return value from
+	# run_merge_cmd is simply the tool's exit code, and check_unchanged()
+	# is not called.
+	#
+	# The return value of exit_code_trustable() tells us whether or not we
+	# can trust the tool's exit code.
+	#
+	# User-defined and built-in tools default to false.
+	# Built-in tools advertise that their exit code is trustable by
+	# redefining exit_code_trustable() to true.
+
+	exit_code_trustable () {
+		false
+	}
+
+
 	if ! test -f "$MERGE_TOOLS_DIR/$tool"
 	then
 		setup_user_tool
@@ -197,6 +210,19 @@ get_merge_tool_cmd () {
 	fi
 }
 
+trust_exit_code () {
+	if git config --bool "mergetool.$1.trustExitCode"
+	then
+		:; # OK
+	elif exit_code_trustable
+	then
+		echo true
+	else
+		echo false
+	fi
+}
+
+
 # Entry point for running tools
 run_merge_tool () {
 	# If GIT_PREFIX is empty then we cannot use it in tools
@@ -225,7 +251,15 @@ run_diff_cmd () {
 
 # Run a either a configured or built-in merge tool
 run_merge_cmd () {
-	merge_cmd "$1"
+	mergetool_trust_exit_code=$(trust_exit_code "$1")
+	if test "$mergetool_trust_exit_code" = "true"
+	then
+		merge_cmd "$1"
+	else
+		touch "$BACKUP"
+		merge_cmd "$1"
+		check_unchanged
+	fi
 }
 
 list_merge_tool_candidates () {
@@ -305,6 +339,7 @@ guess_merge_tool () {
 	EOF
 
 	# Loop over each candidate and stop when a valid merge tool is found.
+	IFS=' '
 	for tool in $tools
 	do
 		is_available "$tool" && echo "$tool" && return 0
@@ -371,3 +406,28 @@ get_merge_tool () {
 	fi
 	echo "$merge_tool"
 }
+
+mergetool_find_win32_cmd () {
+	executable=$1
+	sub_directory=$2
+
+	# Use $executable if it exists in $PATH
+	if type -p "$executable" >/dev/null 2>&1
+	then
+		printf '%s' "$executable"
+		return
+	fi
+
+	# Look for executable in the typical locations
+	for directory in $(env | grep -Ei '^PROGRAM(FILES(\(X86\))?|W6432)=' |
+		cut -d '=' -f 2- | sort -u)
+	do
+		if test -n "$directory" && test -x "$directory/$sub_directory/$executable"
+		then
+			printf '%s' "$directory/$sub_directory/$executable"
+			return
+		fi
+	done
+
+	printf '%s' "$executable"
+}