Segmentation fault when running recursive traps

[Eduardo A . Bustamante López]

I know that a recursive trap in a script is probably a bug, but I think that it
shouldn't make bash segfault:

| dualbus@hp ...local/src/bash % ./bash -c 'trap "kill \$\$" TERM; kill $$'
| [...]
| ./bash: line 1: warning: run_pending_traps: recursive invocation while 
running trap for signal 15
| ./bash: line 1: warning: run_pending_traps: recursive invocation while 
running trap for signal 15
| ./bash: line 1: warning: run_pending_traps: recursive invocation while 
running trap for signal 15
| ./bash: line 1: warning: run_pending_traps: recursive invocation while 
running trap for signal 15
| ./bash: line 1: warning: run_pending_traps: recursive invocation while 
running trap for signal 15
| zsh: segmentation fault  ./bash -c 'trap "kill \$\$" TERM; kill $$'

Other shells that also segfault:
- dash:
    | dualbus@hp ~/local/src/dash-0.5.8
    |  % ./src/dash -c 'trap "kill \$\$" TERM; kill $$' 
    |  zsh: segmentation fault  ./src/dash -c 'trap "kill \$\$" TERM; kill $$'
- mksh:
    | dualbus@hp ~ % mksh -c 'echo $KSH_VERSION'
    | @(#)MIRBSD KSH R50 2014/10/19
- busybox sh:
    |dualbus@hp ~ % busybox sh -c 'trap "kill \$\$" TERM; kill $$' 
    |zsh: segmentation fault  busybox sh -c 'trap "kill \$\$" TERM; kill $$'
    |dualbus@hp ~ % busybox|head -n1
    |BusyBox v1.22.1 (Debian 1:1.22.0-13) multi-call binary.

Shells that do not:
- zsh
- ksh93
- heirloom's

(BTW, I do know that I should be doing: 
| -c 'trap "trap - TERM; kill \$\$"; kill $$',
but, my point is that it should probably have a recursion limit, just like
functions have)