From: Sam Leonard <sam.leonard@codethink.co.uk>
Date: Tue, 27 Feb 2024 11:12:39 +0000 (+0000)
Subject: basic/terminal-util: add check for poll timeout in get_default_background_color
X-Git-Tag: v256-rc1~708^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9924d3c595958982b331c7e5f326bb3a4c1c7db6;p=thirdparty%2Fsystemd.git

basic/terminal-util: add check for poll timeout in get_default_background_color

Currently the return value 0 is not checked for, this indicates a
timeout and should be handled to prevent doing a blocking read on a file
descriptor with no data ready.
---

diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c
index 4c1824bc83f..aa1cf7cfff7 100644
--- a/src/basic/terminal-util.c
+++ b/src/basic/terminal-util.c
@@ -1744,6 +1744,10 @@ int get_default_background_color(double *ret_red, double *ret_green, double *ret
                 r = fd_wait_for_event(STDIN_FILENO, POLLIN, usec_sub_unsigned(end, n));
                 if (r < 0)
                         goto finish;
+                if (r == 0) {
+                        r = -EOPNOTSUPP;
+                        goto finish;
+                }
 
                 ssize_t l;
                 l = read(STDIN_FILENO, buf, sizeof(buf) - buf_full);