[hackers] [svkbd] check key for NULL dereference, just in case || Hiltjo Posthuma

[git]

commit 81c96cec89dd280cab71170f50b9c088476d263c
Author:     Hiltjo Posthuma <hil...@codemadness.org>
AuthorDate: Sat Jul 3 11:44:18 2021 +0200
Commit:     Hiltjo Posthuma <hil...@codemadness.org>
CommitDate: Sat Jul 3 11:44:18 2021 +0200

    check key for NULL dereference, just in case
    
    This matches the check pattern in other parts of the code.

diff --git a/svkbd.c b/svkbd.c
index d80103a..68a2062 100644
--- a/svkbd.c
+++ b/svkbd.c
@@ -643,7 +643,8 @@ unpress(Key *k, KeySym buttonmod)
                }
        }
 
-       if (enableoverlays && currentoverlay != -1 && 
!IsModifierKey(k->keysym)) {
+       if (enableoverlays && currentoverlay != -1 &&
+           (k == NULL || !IsModifierKey(k->keysym))) {
                if (releaseprotect) {
                        releaseprotect = 0;
                } else {