Re: [PATCH] http API: fix dangling pointer issue noted by GCC 12.0

[Junio C Hamano <gitster@pobox.com>]

Junio C Hamano <gitster@pobox.com> writes:

> I am puzzled by this error.  The assignment is the only one that
> assigns a real pointer to the .finished member, and until
> finish_active_slot() is called on the slot, the loop would not
> leave.  I would understand the error if slot->finished is used after
> the function returns to the caller, but I do not think it is the
> case.

IOW, I am wondering if this is a mistaken compiler that needs to be
told not to raise a false warning.

If the motivation behind the original "do not get fooled by a reused
slot still working on somebody else's request---instead return when
our request is done" was indeed what I speculated, then the pointer
slot->finished when we leave this function should not matter to
anybody.  Would the following patch make the compiler realize that
we never smuggle a local variable's address out of this function via
a pointer in the structure?

 http.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git c/http.c w/http.c
index 229da4d148..85437b1980 100644
--- c/http.c
+++ w/http.c
@@ -1367,6 +1367,9 @@ void run_active_slot(struct active_request_slot *slot)
 			select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
 		}
 	}
+
+	if (slot->finished == &finished)
+		slot->finished = NULL;
 }
 
 static void release_active_slot(struct active_request_slot *slot)