https://gitlab.freedesktop.org/pipewire/pipewire/-/commit/40552a0e914c3aef48ce59ce1bfb9d80516aa893

From 40552a0e914c3aef48ce59ce1bfb9d80516aa893 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Tue, 12 Jul 2022 15:10:02 +0200
Subject: [PATCH] jack: only mix when we have input to mix

Avoids a crash when starting ardour6.
--- a/pipewire-jack/src/pipewire-jack.c
+++ b/pipewire-jack/src/pipewire-jack.c
@@ -4449,7 +4449,7 @@ static void *get_buffer_input_float(struct port *p, jack_nframes_t frames)
 	}
 	if (n_ptr == 1) {
 		ptr = mix_ptr[0];
-	} else {
+	} else if (n_ptr > 1) {
 		ptr = p->emptyptr;
 		mix_function(ptr, mix_ptr, n_ptr, ptr_aligned, frames);
 		p->zeroed = false;
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