[Toybox] [PATCH 2] Fix segfault in config2help

[Patrick Oppenlander]

For some reason config2help started segfaulting on me.

I haven't had time to completely track down the reason for this, but it seems that under some conditions sym->help is left dangling after memory is free'd by:

         // Append trailing lines.
         while (tfrom) dlist_add(&anchor, dlist_zap(&tfrom));

Either way, testing sym->enabled appears to fix the problem.

============8<===============

commit 6c892548ad623ffe2b026139d7f22efb7763f024 (HEAD -> master)
Author: Patrick Oppenlander <patrick.oppenlander at gmail.com>
Date:   Thu Sep 21 15:37:42 2017 +1000

     fix segfault in config2help
     
     Somehow sym->help can be left non-null after trailing lines are appended.
     
     Fix by not attempting to print help for disabled symbols.

diff --git a/scripts/config2help.c b/scripts/config2help.c
index d238939..cdb250d 100644
--- a/scripts/config2help.c
+++ b/scripts/config2help.c
@@ -397,7 +397,7 @@ int main(int argc, char *argv[])
    while (sym) {
      struct double_list *dd;
  
-    if (sym->help) {
+    if (sym->help && sym->enabled) {
        int i;
        char *s = xstrdup(sym->name);