}
setup_environment();
-exec(generate_command());
+
+# ActiveState Perl for Win32 does not implement POSIX semantics of
+# exec* system call. It just spawns the given executable and finishes
+# the starting program, exiting with code 0.
+# system will at least catch the errors returned by git diff,
+# allowing the caller of git difftool better handling of failures.
+my $rc = system(generate_command());
+exit($rc | ($rc >> 8));