[sysprof] sysprofd: ftruncate() when overwriting files

[Christian Hergert <chergert src gnome org>]

commit 4777e74862be35b6a31886933dbaae820c65b370
Author: Christian Hergert <chergert redhat com>
Date:   Wed Feb 24 13:03:24 2021 -0800

    sysprofd: ftruncate() when overwriting files
    
    This is really only used for proc like files which are generally a single
    page, but might as well start from zero.

 src/sysprofd/ipc-service-impl.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/sysprofd/ipc-service-impl.c b/src/sysprofd/ipc-service-impl.c
index da9bf47..3722908 100644
--- a/src/sysprofd/ipc-service-impl.c
+++ b/src/sysprofd/ipc-service-impl.c
@@ -78,6 +78,8 @@ file_set_contents_no_backup (const gchar  *path,
       return FALSE;
     }
 
+  ftruncate (fd, 0);
+
   if (write (fd, contents, len) != len)
     {
       int errsv = errno;