properties: handle checkonly flag.

if checkonly is TRUE, only check the values but do not apply them. This is
achieved by working on a temporary copy of the parameters if checkonly is set,
and ditching the copy after completion.
If checkout is not set, the same code works on the actual parameters.

Signed-off-by: Peter Hutterer <peter.hutterer@redhat.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/src/properties.c b/src/properties.c
index aa197f2..ea348cc 100644
--- a/src/properties.c
+++ b/src/properties.c
@@ -208,11 +208,21 @@ InitDeviceProperties(LocalDevicePtr local)
 }
 
 int
-SetProperty(DeviceIntPtr dev, Atom property, XIPropertyValuePtr prop)
+SetProperty(DeviceIntPtr dev, Atom property, XIPropertyValuePtr prop,
+            BOOL checkonly)
 {
     LocalDevicePtr local = (LocalDevicePtr) dev->public.devicePrivate;
     SynapticsPrivate *priv = (SynapticsPrivate *) local->private;
     SynapticsSHM *para = priv->synpara;
+    SynapticsSHM tmp;
+
+    /* If checkonly is set, no parameters may be changed. So just let the code
+     * change temporary variables and forget about it. */
+    if (checkonly)
+    {
+        tmp = *para;
+        para = &tmp;
+    }
 
     if (property == prop_edges)
     {