From c37ebd3f1aae8b3faf238cdca9789f1ca079f52c Mon Sep 17 00:00:00 2001
From: scgbckbone <scgbckbone@proton.me>
Date: Wed, 5 Apr 2023 19:20:37 +0200
Subject: [PATCH] zero output test; limitations update

---
 docs/limitations.md  |  1 +
 shared/psbt.py       |  2 +-
 testing/test_sign.py | 26 ++++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/docs/limitations.md b/docs/limitations.md
index 329df444..22b51c4a 100644
--- a/docs/limitations.md
+++ b/docs/limitations.md
@@ -48,6 +48,7 @@
 - bitcoin limits transactions to 100k, but there could be large input transactions
   inside the PSBT. Reduce this by using segwit signatures and provide only the
   individual UTXO ("out points").
+- every transaction needs to have at least one output (otherwise Invalid PSBT)
 
 
 # P2SH / Multisig
diff --git a/shared/psbt.py b/shared/psbt.py
index f7e7e03e..b7e93f94 100644
--- a/shared/psbt.py
+++ b/shared/psbt.py
@@ -1162,7 +1162,7 @@ class psbtObject(psbtProxy):
         if self.xpubs:
             await self.handle_xpubs()
 
-        assert self.num_outputs >= 1, 'need outs'
+        assert self.num_outputs >= 1, 'need outputs'
 
         if DEBUG:
             our_keys = sum(1 for i in self.inputs if i.num_our_keys)
diff --git a/testing/test_sign.py b/testing/test_sign.py
index 9e9975f8..b00f8b3e 100644
--- a/testing/test_sign.py
+++ b/testing/test_sign.py
@@ -1941,4 +1941,30 @@ def test_sighash_all(addr_fmt, num_outs, microsd_path, need_keypress, goto_home,
     # tx with 6 inputs representing all possible sighashes
     _test_single_sig_sighash(addr_fmt, tuple(SIGHASH_MAP.keys()), num_inputs=6, num_outputs=num_outs)
 
+
+def test_no_outputs_tx(fake_txn, microsd_path, goto_home, need_keypress, pick_menu_item, cap_story):
+    goto_home()
+    psbt = fake_txn(3, 0)  # no outputs
+    fname = "zero_outputs.psbt"
+    fpath = microsd_path(fname)
+
+    with open(fpath, "wb") as f:
+        f.write(psbt)
+
+    pick_menu_item("Ready To Sign")
+    time.sleep(0.1)
+    title, story = cap_story()
+    if "Choose PSBT file to be signed" in story:
+        need_keypress("y")
+        pick_menu_item(fname)
+        time.sleep(0.1)
+        title, story = cap_story()
+
+    assert title == "Failure"
+    assert "Invalid PSBT" in story
+    assert "need outputs" in story
+
+    try: os.remove(fpath)
+    except: pass
+
 # EOF