From 94dfd1655efffc52a57e76130f11b6e0af0f8dd8 Mon Sep 17 00:00:00 2001
From: Erick Sanchez <7268597+nalancer08@users.noreply.github.com>
Date: Mon, 26 Oct 2026 11:10:48 -0600
Subject: [PATCH] Count unique archives when estimating extraction space

Adapted from upstream PR #277 (841684012800327d6d6fa6b6fd79d3ab689c9751).
---
 dm/tools/tests/test_nsp_space.py | 33 ++++++++++++++++++++++++++++++++
 scripts/build_ipa_from_nsp.py    |  6 +++++-
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 dm/tools/tests/test_nsp_space.py

diff --git a/dm/tools/tests/test_nsp_space.py b/dm/tools/tests/test_nsp_space.py
new file mode 100644
index 0000000..65d2e0a
--- /dev/null
+++ b/dm/tools/tests/test_nsp_space.py
@@ -0,0 +1,33 @@
+"""NSP extraction space estimate: distinct archives count even when they have the same size; the shared base counts once.
+No game files, keys or Xcode needed (temporary synthetic files only)."""
+import importlib.util
+from pathlib import Path
+import tempfile
+import unittest
+
+REPO = Path(__file__).resolve().parents[3]
+spec = importlib.util.spec_from_file_location('build_ipa_from_nsp', REPO / 'scripts/build_ipa_from_nsp.py')
+nsp = importlib.util.module_from_spec(spec); spec.loader.exec_module(nsp)
+
+
+class Space(unittest.TestCase):
+    def test_equal_sized_archives(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            base, update = Path(tmp) / 'base.nsp', Path(tmp) / 'update.nsp'
+            base.write_bytes(b'base'); update.write_bytes(b'updt')
+            self.assertEqual(nsp.picked_nsp_bytes({'v1': (base, update)}), 8)
+
+    def test_shared_base(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            base, first, second = [Path(tmp) / name for name in ('base.nsp', 'first.nsp', 'second.nsp')]
+            base.write_bytes(b'base'); first.write_bytes(b'first'); second.write_bytes(b'second')
+            self.assertEqual(nsp.picked_nsp_bytes({'v0': (base, None), 'v1': (base, first), 'v2': (base, second)}), 15)
+
+    def test_base_without_update(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            base = Path(tmp) / 'base.nsp'; base.write_bytes(b'base')
+            self.assertEqual(nsp.picked_nsp_bytes({'v0': (base, None)}), 4)
+
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/scripts/build_ipa_from_nsp.py b/scripts/build_ipa_from_nsp.py
index c5a189a..66a2794 100755
--- a/scripts/build_ipa_from_nsp.py
+++ b/scripts/build_ipa_from_nsp.py
@@ -490,6 +490,10 @@ def pick_nsps(fam, have, versions):
     return out
 
 
+def picked_nsp_bytes(picks):   # count each archive once, not each distinct size (the base occurs in every version)
+    return sum(p.stat().st_size for p in {p for base, update in picks.values() for p in (base, update) if p is not None})
+
+
 def can_clone(d):   # whether this volume supports APFS clones (nx_extract uses them to save space; without them it writes full copies)
     a, b = d / '.clone_test', d / '.clone_test2'
     try:
@@ -1750,7 +1754,7 @@ def main(args=None):
     picks = pick_nsps(fam, have, versions)
 
     ex = work / 'extract'; ex.mkdir(parents=True, exist_ok=True); (work / 'tmp').mkdir(exist_ok=True)
-    gb = sum({p.stat().st_size for b, u in picks.values() for p in (b, u) if p}) / 2**30 + 6   # extraction + shader cache + slack
+    gb = picked_nsp_bytes(picks) / 2**30 + 6   # extraction + shader cache + slack
     if free_gb(work) < gb and not all((ex / v).exists() for v in versions): raise BuildError(f'less than {gb:.0f} GB free on the volume of {work}')
     heapck = provisional and HEAP_CHECK and not args.no_heap_check and not heap_checked(g)   # the heap check, when the game needs one (once per provisional profile: it stamps the profile)
     PROG.plan(1 + len(versions) + bool(fam['dlc']) + 4 - (prepare_xcode or (mac and not mac_pack)))   # prepare Xcode (a Mac-only build: the Mac host) replaces app build + IPA pack with one stage (a Mac app: Mac host + Mac app)