libredirect: add posix_spawnp support

After bumping sublime3 in #61636 we realized that saving files as root
doesn’t work anymore and somehow the paths weren’t patched by
`libredirect`.

After some debugging it came out that Sublime switched from `posix_spawn(3)`
to `posix_spawnp(3)` to start new processes internally. Since `libredirect`
only handled the former, `/usr/bin/pkexec` stopped being redirected.

Wrapping `posix_spawnp` fixes the problem.

1 files changed, 13 insertions, 0 deletions

diff --git a/pkgs/build-support/libredirect/libredirect.c b/pkgs/build-support/libredirect/libredirect.c
index 655399af58f..8e8da00b02a 100644
--- a/pkgs/build-support/libredirect/libredirect.c
+++ b/pkgs/build-support/libredirect/libredirect.c
@@ -160,6 +160,19 @@ int posix_spawn(pid_t * pid, const char * path,
     return posix_spawn_real(pid, rewrite(path, buf), file_actions, attrp, argv, envp);
 }
 
+int posix_spawnp(pid_t * pid, const char * file,
+    const posix_spawn_file_actions_t * file_actions,
+    const posix_spawnattr_t * attrp,
+    char * const argv[], char * const envp[])
+{
+    int (*posix_spawnp_real) (pid_t *, const char *,
+        const posix_spawn_file_actions_t *,
+        const posix_spawnattr_t *,
+        char * const argv[], char * const envp[]) = dlsym(RTLD_NEXT, "posix_spawnp");
+    char buf[PATH_MAX];
+    return posix_spawnp_real(pid, rewrite(file, buf), file_actions, attrp, argv, envp);
+}
+
 int execv(const char *path, char *const argv[])
 {
     int (*execv_real) (const char *path, char *const argv[]) = dlsym(RTLD_NEXT, "execv");