Fix validation of ctrls parameter to XkbGetPerClientControls()

Nothing in the XKB spec states that the memory pointed to by ctrls has to be initialized to any given value when passed to the function, only that it is set by the function to the values returned by the X server: http://www.x.org/releases/X11R7.7/doc/libX11/XKB/xkblib.html#The_Miscellaneous_Per_client_Controls The check for the incoming value seems to be copied from XkbSetPerClientControls without explanation. Instead change it to checking if ctrls is non-NULL, since there's no point asking the X server to return a value the caller won't even see. Found while investigating report from cppcheck-1.65: [nx-X11/lib/X11/XKB.c:699] -> [nx-X11/lib/X11/XKB.c:719]: (warning) Possible null pointer dereference: ctrls - otherwise it is redundant to check it against null. Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com> Backported-to-NX-by: Ulrich Sibiller <uli42@gmx.de>

Fix validation of ctrls parameter to XkbGetPerClientControls()
f20f91ee · Alan Coopersmith · Ulrich Sibiller · 37b8d688 · f20f91ee
Commit f20f91ee authored Jul 06, 2014 by Alan Coopersmith Committed by Ulrich Sibiller Oct 19, 2016
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XKB.c nx-X11/lib/X11/XKB.c +4 -7

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--- a/nx-X11/lib/X11/XKB.c
+++ b/nx-X11/lib/X11/XKB.c
@@ -696,9 +696,7 @@ XkbGetPerClientControls(Display *dpy, unsigned *ctrls)

    if ((dpy->flags & XlibDisplayNoXkb) ||
        (!dpy->xkb_info && !XkbUseExtension(dpy, NULL, NULL)) ||
-        (*ctrls & ~(XkbPCF_GrabsUseXKBStateMask |
-                    XkbPCF_LookupStateWhenGrabbed |
-                    XkbPCF_SendEventUsesXKBState)))
+        (ctrls == NULL))
        return False;
    LockDisplay(dpy);
    xkbi = dpy->xkb_info;
@@ -716,10 +714,9 @@ XkbGetPerClientControls(Display *dpy, unsigned *ctrls)
    }
    UnlockDisplay(dpy);
    SyncHandle();
-    if (ctrls)
-        *ctrls = (rep.value & (XkbPCF_GrabsUseXKBStateMask |
-                               XkbPCF_LookupStateWhenGrabbed |
-                               XkbPCF_SendEventUsesXKBState));
+    *ctrls = (rep.value & (XkbPCF_GrabsUseXKBStateMask |
+                           XkbPCF_LookupStateWhenGrabbed |
+                           XkbPCF_SendEventUsesXKBState));
    return (True);
 }