Re: exported unset variables [was: 'export -p' lacks POSIX output]

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Oct 29,  9:11am, Martijn Dekker wrote:
} Subject: Re: exported unset variables [was: 'export -p' lacks POSIX output
}
} % var=; echo ${var+set} ${var-unset}; typeset -p var
} set
} typeset var=''
} 
} The variable name loses its export attribute upon assignment; it should
} retain it.

That one potentially gets rather ugly; consider:

% setopt POSIXBUILTINS
% export var
% var=()
zsh: var: attempt to assign array value to non-array

Is that OK with everyone?

As an aside, zsh currently allows the export flag to be applied to array
variables, but then will not put them in the environment.  Patch below
revises 39704 to use "typeset -xa ary" rather than "export -a ary".

Replaces 39754.


diff --git a/Src/builtin.c b/Src/builtin.c
index 2db739f..986ace2 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -2008,11 +2008,12 @@ typeset_single(char *cname, char *pname, Param pm, UNUSED(int func),
      * handled in createparam().  Here we just avoid using it for the
      * present tests if it's unset.
      *
-     * POSIXBUILTINS horror: we need to retain the 'readonly' flag
-     * of an unset parameter.
+     * POSIXBUILTINS horror: we need to retain the 'readonly' or 'export'
+     * flags of an unset parameter.
      */
     usepm = pm && (!(pm->node.flags & PM_UNSET) ||
-		   (isset(POSIXBUILTINS) && (pm->node.flags & PM_READONLY)));
+		   (isset(POSIXBUILTINS) &&
+		    (pm->node.flags & (PM_READONLY|PM_EXPORTED))));
 
     /*
      * We need to compare types with an existing pm if special,
@@ -2135,7 +2136,8 @@ typeset_single(char *cname, char *pname, Param pm, UNUSED(int func),
 	/*
 	 * Stricter rules about retaining readonly attribute in this case.
 	 */
-	if ((on & PM_READONLY) && (!usepm || (pm->node.flags & PM_UNSET)) &&
+	if ((on & (PM_READONLY|PM_EXPORTED)) &&
+	    (!usepm || (pm->node.flags & PM_UNSET)) &&
 	    !ASG_VALUEP(asg))
 	    on |= PM_UNSET;
 	else if (usepm && (pm->node.flags & PM_READONLY) &&
@@ -2143,6 +2145,10 @@ typeset_single(char *cname, char *pname, Param pm, UNUSED(int func),
 	    zerr("read-only variable: %s", pm->node.nam);
 	    return NULL;
 	}
+	/* This is handled by createparam():
+	if (usepm && (pm->node.flags & PM_EXPORTED) && !(off & PM_EXPORTED))
+	    on |= PM_EXPORTED;
+	*/
     }
 
     /*
diff --git a/Src/params.c b/Src/params.c
index 3084b1f..330f22b 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -940,7 +940,10 @@ createparam(char *name, int flags)
 		zerr("%s: restricted", name);
 		return NULL;
 	    }
-	    if (!(oldpm->node.flags & PM_UNSET) || (oldpm->node.flags & PM_SPECIAL)) {
+	    if (!(oldpm->node.flags & PM_UNSET) ||
+		(oldpm->node.flags & PM_SPECIAL) ||
+		/* POSIXBUILTINS horror: we need to retain 'export' flags */
+		(isset(POSIXBUILTINS) && (oldpm->node.flags & PM_EXPORTED))) {
 		oldpm->node.flags &= ~PM_UNSET;
 		if ((oldpm->node.flags & PM_SPECIAL) && oldpm->ename) {
 		    Param altpm =
@@ -5225,10 +5228,6 @@ printparamvalue(Param p, int printflags)
 {
     char *t, **u;
 
-    if ((p->node.flags & PM_EXPORTED) && !p->env) {
-	putchar('\n');
-	return;
-    }
     if (printflags & PRINT_KV_PAIR)
 	putchar(' ');
     else
@@ -5332,7 +5331,8 @@ printparamnode(HashNode hn, int printflags)
 	}
 	if (locallevel && p->level >= locallevel) {
 	    printf("typeset ");	    /* printf("local "); */
-	} else if (p->node.flags & PM_EXPORTED) {
+	} else if ((p->node.flags & PM_EXPORTED) &&
+		   !(p->node.flags & (PM_ARRAY|PM_HASHED))) {
 	    printf("export ");
 	} else if (locallevel) {
 	    printf("typeset -g ");
@@ -5350,8 +5350,8 @@ printparamnode(HashNode hn, int printflags)
 	    if (pmptr->flags & PMTF_TEST_LEVEL) {
 		if (p->level)
 		    doprint = 1;
-	    } else if ((pmptr->binflag != PM_EXPORTED ||
-			((p->node.flags & PM_LOCAL) || p->level)) &&
+	    } else if ((pmptr->binflag != PM_EXPORTED || p->level ||
+			(p->node.flags & (PM_LOCAL|PM_ARRAY|PM_HASHED))) &&
 		       (p->node.flags & pmptr->binflag))
 		doprint = 1;