Re: syntax check of 'echo $HOME' crashes in ksh emulation mode

[Peter Stephenson <p.stephenson@samsung.com>]

On Mon, 5 Oct 2015 18:09:22 +0200
Kamil Dudka <kdudka@redhat.com> wrote:
> The following command causes a SIGSEGV in zsh (built from upstream git HEAD):
> 
> $ ARGV0=ksh zsh -nc 'echo $HOME'
> zsh: segmentation fault (core dumped)  ARGV0=ksh Src/zsh -nc 'echo $HOME'

I'm not sure if we need to be more careful in paramsubst(), too, but if
we're not setting HOME because this is ksh emulation we should certainly
say so.

pws

diff --git a/Src/params.c b/Src/params.c
index de151a4..a8abb28 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -775,17 +775,18 @@ createparamtable(void)
 #endif
     opts[ALLEXPORT] = oae;
 
+    /*
+     * For native emulation we always set the variable home
+     * (see setupvals()).
+     */
+    pm = (Param) paramtab->getnode(paramtab, "HOME");
     if (EMULATION(EMULATE_ZSH))
     {
-	/*
-	 * For native emulation we always set the variable home
-	 * (see setupvals()).
-	 */
-	pm = (Param) paramtab->getnode(paramtab, "HOME");
 	pm->node.flags &= ~PM_UNSET;
 	if (!(pm->node.flags & PM_EXPORTED))
 	    addenv(pm, home);
-    }
+    } else if (!home)
+	pm->node.flags |= PM_UNSET;
     pm = (Param) paramtab->getnode(paramtab, "LOGNAME");
     if (!(pm->node.flags & PM_EXPORTED))
 	addenv(pm, pm->u.str);