Coverity ID 327264 - move pointer NULL check

Due to recent changes in this code, the pointer was being dereferenced
before we checked it to see if it was NULL. Moe the check so that we
check for NULL before dereferencing.

The 'pvalue' of the operand can be NULL, even if the object is a t_device
type, because invalidate_stack_devices traverses the operand stack
looking for devices, and sets their pvalue member to NULL in order to
invalidate them so that they cannot be used.

1 files changed, 3 insertions, 3 deletions

diff --git a/psi/zdevice.c b/psi/zdevice.c
index bd2c542fb..eb6d1b1cf 100644
--- a/psi/zdevice.c
+++ b/psi/zdevice.c
@@ -518,6 +518,9 @@ zsetdevice(i_ctx_t *i_ctx_p)
         return code;
     check_write_type(*op, t_device);
 
+    if (op->value.pdevice == 0)
+        return gs_note_error(gs_error_undefined);
+
     /* slightly icky special case: the new device may not have had
      * it's procs initialised, at this point - but we need to check
      * whether we're being asked to change the device here
@@ -537,9 +540,6 @@ zsetdevice(i_ctx_t *i_ctx_p)
     }
     dev->ShowpageCount = 0;
 
-    if (op->value.pdevice == 0)
-        return gs_note_error(gs_error_undefined);
-
     code = gs_setdevice_no_erase(igs, op->value.pdevice);
     if (code < 0)
         return code;