Re: [PATCH] dash: Fix stack overflow from infinite recursion in script

[Steffen Nurpmeso <steffen@xxxxxxxxxx>]

Andrej Shadura wrote in <20190718153028.18791-1-andrew.shadura@collabora\
.co.uk>:
 |From: Chris Lamb <lamby@xxxxxxxxxx>
 |
 |Bug-Debian: https://bugs.debian.org/579815
 |Signed-off-by: Chris Lamb <lamby@xxxxxxxxxx>
 |Signed-off-by: Andrej Shadura <andrew.shadura@xxxxxxxxxxxxxxx>
  ...
 |+static int evalcount;                /* number of nested evalfun calls */
 ...
 |+             if (evalcount++ >= MAX_RECURSION)
 |+                     sh_error("Maximum function recursion depth (%d) \
 ...
 |+#define MAX_RECURSION 1000   /* maximum recursion level */

A couple of years ago i discovered mksh was crashing due to not
having such a limit, and in the discussion which started with
Thorsten (the mksh developer) it became obvious that a then-new
bash seemed to have stopped using a limit; Thorsten's point was
that the real limit can only be artitificial or very costly (if
i recall correctly).  By then i sent Mr. Xu a message in private
with i think a summary of all that, but never got any response.
I know that the Lua scripting language seems be in the process of
introducing such a limit with the upcoming release.

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)