subprocess-posix: always connect stdin to /dev/null

It appears youtube-dl sometimes asks for a password on stdin. This won't
work, because mpv already uses the terminal.

(I wonder if this could be simpler, like simply closing FD 0, but let's
not. The FD would be reused by something random.)

1 files changed, 12 insertions, 1 deletions

diff --git a/osdep/subprocess-posix.c b/osdep/subprocess-posix.c
index c2120b2aa8..9d565f411e 100644
--- a/osdep/subprocess-posix.c
+++ b/osdep/subprocess-posix.c
@@ -20,6 +20,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <fcntl.h>
 #include <errno.h>
 #include <signal.h>
 
@@ -63,6 +64,7 @@ int mp_subprocess(char **args, struct mp_cancel *cancel, void *ctx,
     int status = -1;
     int p_stdout[2] = {-1, -1};
     int p_stderr[2] = {-1, -1};
+    int devnull = -1;
     pid_t pid = -1;
 
     if (on_stdout && mp_make_cloexec_pipe(p_stdout) < 0)
@@ -70,10 +72,16 @@ int mp_subprocess(char **args, struct mp_cancel *cancel, void *ctx,
     if (on_stderr && mp_make_cloexec_pipe(p_stderr) < 0)
         goto done;
 
+    devnull = open("/dev/null", O_RDONLY | O_CLOEXEC);
+    if (devnull < 0)
+        goto done;
+
     if (posix_spawn_file_actions_init(&fa))
         goto done;
     fa_destroy = true;
-    // redirect stdout and stderr
+    // redirect stdin/stdout/stderr
+    if (posix_spawn_file_actions_adddup2(&fa, devnull, 0))
+        goto done;
     if (p_stdout[1] >= 0 && posix_spawn_file_actions_adddup2(&fa, p_stdout[1], 1))
         goto done;
     if (p_stderr[1] >= 0 && posix_spawn_file_actions_adddup2(&fa, p_stderr[1], 2))
@@ -88,6 +96,8 @@ int mp_subprocess(char **args, struct mp_cancel *cancel, void *ctx,
     p_stdout[1] = -1;
     close(p_stderr[1]);
     p_stderr[1] = -1;
+    close(devnull);
+    devnull = -1;
 
     int *read_fds[2] = {&p_stdout[0], &p_stderr[0]};
     subprocess_read_cb read_cbs[2] = {on_stdout, on_stderr};
@@ -133,6 +143,7 @@ done:
     close(p_stdout[1]);
     close(p_stderr[0]);
     close(p_stderr[1]);
+    close(devnull);
 
     if (WIFEXITED(status) && WEXITSTATUS(status) != 127) {
         *error = NULL;