diff --git a/builtin/merge.c b/builtin/merge.c
index ed0f959ac49c02aaffa77bc748a9efc69f1fd339..d3e1e8dc9e478aaea7ef4da855fb7c2e10397644 100644 (file)
--- a/builtin/merge.c
+++ b/builtin/merge.c
/* Use editor if stdin and stdout are the same and is a tty */
return (!fstat(0, &st_stdin) &&
!fstat(1, &st_stdout) &&
- isatty(0) &&
+ isatty(0) && isatty(1) &&
st_stdin.st_dev == st_stdout.st_dev &&
st_stdin.st_ino == st_stdout.st_ino &&
st_stdin.st_mode == st_stdout.st_mode);