This bug was originally reported by @lijog in att/ast#7 and has been
reported again in #15. KSH does not save the state of a variable if it
is in a newer scope. This is because of an optimization in sh_assignok
first introduced in ksh93t+ 2010-05-24. Here is the code change in that
version:
return(np);
/* don't bother to save if in newer scope */
- if(!(rp=shp->st.real_fun) || !(dp=rp->sdict))
- dp = sp->var;
- if(np->nvenv && !nv_isattr(np,NV_MINIMAL|NV_EXPORT) && shp->last_root)
- dp = shp->last_root;
- if((mp=nv_search((char*)np,dp,HASH_BUCKET))!=np)
- {
- if(mp || !np->nvfun || np->nvfun->subshell>=sh.subshell)
- return(np);
- }
+ if(sp->var!=shp->var_tree && shp->last_root==shp->var_tree)
+ return(np);
if((ap=nv_arrayptr(np)) && (mp=nv_opensub(np)))
{
This change was originally made to replace a buggier optimization.
However, the current optimization causes variables set in subshells
to wrongly affect the environment outside of the subshell, as the
variable does not get set back to its original value. This patch
simply removes the buggy optimization to fix this problem.
src/cmd/ksh93/sh/subshell.c:
- Remove a buggy optimization that caused variables set in subshells
to affect the environment outside of the subshell.
src/cmd/ksh93/tests/subshell.sh:
- Add a regression test for setting variables in subshells. This
test has to be run from the disk after being created with a here
document because it always returns the expected result when run
directly in the regression test script.
3d38270b32