zcat: fix "zcat FILE" trying to do detection twice

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 7 insertions, 8 deletions

diff --git a/archival/bbunzip.c b/archival/bbunzip.c
index 54dc2f5f1..d59c65571 100644
--- a/archival/bbunzip.c
+++ b/archival/bbunzip.c
@@ -66,12 +66,17 @@ int FAST_FUNC bbunpack(char **argv,
                                 if (open_to_or_warn(STDIN_FILENO, filename, O_RDONLY, 0))
                                         goto err;
                         } else {
-                                /* "clever zcat" */
+                                /* "clever zcat" with FILE */
                                 int fd = open_zipped(filename);
                                 if (fd < 0)
                                         goto err_name;
                                 xmove_fd(fd, STDIN_FILENO);
                         }
+                } else
+                if (option_mask32 & SEAMLESS_MAGIC) {
+                        /* "clever zcat" on stdin */
+                        if (setup_unzip_on_fd(STDIN_FILENO, /*fail_if_not_detected*/ 0))
+                                goto err;
                 }
 
                 /* Special cases: test, stdout */
@@ -115,15 +120,9 @@ int FAST_FUNC bbunpack(char **argv,
                         if (status < 0)
                                 exitcode = 1;
                 } else {
-                        /* "clever zcat" */
-                        if (!filename) {
-                                if (setup_unzip_on_fd(STDIN_FILENO, /*fail_if_not_detected*/ 0))
-                                        goto err;
-                        }
-                        if (bb_copyfd_eof(STDIN_FILENO, STDOUT_FILENO) < 0) {
+                        if (bb_copyfd_eof(STDIN_FILENO, STDOUT_FILENO) < 0)
                                 /* Disk full, tty closed, etc. No point in continuing */
                                 xfunc_die();
-                        }
                 }
 
                 if (!(option_mask32 & OPT_STDOUT))