[Libguestfs] [PATCH nbdkit] main: Set umask to a known value and document it for plugins.

[Richard W.M. Jones]

---
 docs/nbdkit-plugin.pod.in | 4 ++++
 src/main.c                | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/docs/nbdkit-plugin.pod.in b/docs/nbdkit-plugin.pod.in
index b6b2e47..22ca40e 100644
--- a/docs/nbdkit-plugin.pod.in
+++ b/docs/nbdkit-plugin.pod.in
@@ -302,6 +302,10 @@ and returns C<NULL>.
 
 The returned string must be freed by the caller.
 
+=head2 umask
+
+All plugins will see a L<umask(2)> of C<0022>.
+
 =head1 CALLBACKS
 
 =head2 C<.name>
diff --git a/src/main.c b/src/main.c
index 660d036..8d901cf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -479,6 +479,12 @@ main (int argc, char *argv[])
     exit (EXIT_FAILURE);
   }
 
+  /* Set the umask to a known value.  This makes the behaviour of
+   * plugins when creating files more predictable, and also removes an
+   * implicit dependency on umask when calling mkstemp(3).
+   */
+  umask (0022);
+
   /* Initialize TLS. */
   crypto_init (tls_set_on_cli);
   assert (tls != -1);
-- 
2.16.2