[PATCH xserver] os: Fix warning in LockServer

Adam Jackson ajax at redhat.com
Wed Aug 30 19:11:45 UTC 2017

The meson build gives me:

../os/utils.c: In function ‘LockServer’:
../os/utils.c:310:40: warning: ‘snprintf’ output may be truncated before the last format character [-Wformat-truncation=]
     snprintf(pid_str, sizeof(pid_str), "%10ld\n", (long) getpid());
../os/utils.c:310:5: note: ‘snprintf’ output between 12 and 13 bytes into a destination of size 12
     snprintf(pid_str, sizeof(pid_str), "%10ld\n", (long) getpid());

Which seems to be due to the %d part meaning that a negative number's -
sign would be one wider than we're expecting. Fine, just coerce it to

Signed-off-by: Adam Jackson <ajax at redhat.com>
 os/utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/os/utils.c b/os/utils.c
index 1972aa120a..8a758f0b9a 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -307,7 +307,7 @@ LockServer(void)
     if (lfd < 0)
         FatalError("Could not create lock file in %s\n", tmp);
-    snprintf(pid_str, sizeof(pid_str), "%10ld\n", (long) getpid());
+    snprintf(pid_str, sizeof(pid_str), "%10lu\n", (unsigned long) getpid());
     if (write(lfd, pid_str, 11) != 11)
         FatalError("Could not write pid to lock file in %s\n", tmp);
     (void) fchmod(lfd, 0444);

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