Re: Memory leak in math expression parser

[Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>]

> On 06/06/2025 04:25 BST Ben Kallus <benjamin.p.kallus.gr@xxxxxxxxxxxxx> wrote:
> Zsh leaks 24 bytes when you run the following command:
> ```
> zsh -c '$((\(<< 0))'
> ```

Yes, that's real, thanks.  Valgrind pointed to assigning a here-document
structure --- this is in a special parse context for the $(...)
subcommand, and the structure isn't freed when that context is popped.

I believe it really is a question of discarding the context completely
at that point, so I think this should do it.

pws

diff --git a/Src/parse.c b/Src/parse.c
index 8edc701..4ce5a46 100644
--- a/Src/parse.c
+++ b/Src/parse.c
@@ -340,6 +340,7 @@ parse_context_restore(const struct parse_stack *ps, int toplevel)
     inrepeat_ = ps->inrepeat_;
     intypeset = ps->intypeset;
 
+    clear_hdocs();
     hdocs = ps->hdocs;
     eclen = ps->eclen;
     ecused = ps->ecused;
@@ -583,6 +584,7 @@ empty_eprog(Eprog p)
     return (!p || !p->prog || *p->prog == WCB_END());
 }
 
+/**/
 static void
 clear_hdocs(void)
 {