[hackers] [dmenu] fix a possible free of a uninitialize variable in paste() || Hiltjo Posthuma

[git]

commit 1cabeda5505dcc35d4d2ca2a09151a7c449fb401
Author:     Hiltjo Posthuma <hil...@codemadness.org>
AuthorDate: Fri Nov 3 15:31:37 2017 +0100
Commit:     Hiltjo Posthuma <hil...@codemadness.org>
CommitDate: Fri Nov 3 21:07:02 2017 +0100

    fix a possible free of a uninitialize variable in paste()

diff --git a/dmenu.c b/dmenu.c
index 91330f1..eae5685 100644
--- a/dmenu.c
+++ b/dmenu.c
@@ -467,10 +467,12 @@ paste(void)
        Atom da;
 
        /* we have been given the current selection, now insert it into input */
-       XGetWindowProperty(dpy, win, utf8, 0, (sizeof text / 4) + 1, False,
-                          utf8, &da, &di, &dl, &dl, (unsigned char **)&p);
-       insert(p, (q = strchr(p, '\n')) ? q - p : (ssize_t)strlen(p));
-       XFree(p);
+       if (XGetWindowProperty(dpy, win, utf8, 0, (sizeof text / 4) + 1, False,
+                          utf8, &da, &di, &dl, &dl, (unsigned char **)&p)
+           == Success && p) {
+               insert(p, (q = strchr(p, '\n')) ? q - p : (ssize_t)strlen(p));
+               XFree(p);
+       }
        drawmenu();
 }