[PATCH] Re: Segfault with "private" parameters inside "always" block

[Bart Schaefer <schaefer@brasslantern.com>]

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On Thu, Jun 9, 2022 at 2:03 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
> zsh/param/private assumes the heap created in startparamscope() is the
> only active heap until endparamscope(), but "always" blocks allocate
> and free another layer of heap, which invalidates the memory "private"
> uses for the parameter GSU structures.

That was a lot simpler/more straightforward than I expected.

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diff --git a/Src/Modules/param_private.c b/Src/Modules/param_private.c
index c53839152..065fa63d2 100644
--- a/Src/Modules/param_private.c
+++ b/Src/Modules/param_private.c
@@ -92,7 +92,7 @@ makeprivate(HashNode hn, UNUSED(int flags))
 	    makeprivate_error = 1;
 	    return;
 	}
-	struct gsu_closure *gsu = zhalloc(sizeof(struct gsu_closure));
+	struct gsu_closure *gsu = zalloc(sizeof(struct gsu_closure));
 	switch (PM_TYPE(pm->node.flags)) {
 	case PM_SCALAR:
 	    gsu->g = (void *)(pm->gsu.s);
@@ -269,6 +269,8 @@ pps_unsetfn(Param pm, int explicit)
 	gsu->unsetfn(pm, explicit);
     if (explicit)
 	pm->gsu.s = (GsuScalar)c;
+    else
+	zfree(c, sizeof(struct gsu_closure));
 }
 
 /**/
@@ -306,6 +308,8 @@ ppi_unsetfn(Param pm, int explicit)
 	gsu->unsetfn(pm, explicit);
     if (explicit)
 	pm->gsu.i = (GsuInteger)c;
+    else
+	zfree(c, sizeof(struct gsu_closure));
 }
 
 /**/
@@ -343,6 +347,8 @@ ppf_unsetfn(Param pm, int explicit)
 	gsu->unsetfn(pm, explicit);
     if (explicit)
 	pm->gsu.f = (GsuFloat)c;
+    else
+	zfree(c, sizeof(struct gsu_closure));
 }
 
 /**/
@@ -381,6 +387,8 @@ ppa_unsetfn(Param pm, int explicit)
 	gsu->unsetfn(pm, explicit);
     if (explicit)
 	pm->gsu.a = (GsuArray)c;
+    else
+	zfree(c, sizeof(struct gsu_closure));
 }
 
 static HashTable emptytable;
@@ -420,6 +428,8 @@ pph_unsetfn(Param pm, int explicit)
 	gsu->unsetfn(pm, explicit);
     if (explicit)
 	pm->gsu.h = (GsuHash)c;
+    else
+	zfree(c, sizeof(struct gsu_closure));
 }
 
 /*