From 0a3cefcb4ef1ba3e042dd3c47108f4c9660cecb7 Mon Sep 17 00:00:00 2001
From: Chris Havlin <chris.havlin@gmail.com>
Date: Thu, 15 Aug 2024 10:43:11 -0500
Subject: [PATCH] bug: tipsy, reading just smoothing length

---
 yt/frontends/tipsy/io.py                 | 5 ++++-
 yt/frontends/tipsy/tests/test_outputs.py | 6 ++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/yt/frontends/tipsy/io.py b/yt/frontends/tipsy/io.py
index 29809570aa..044932fa58 100644
--- a/yt/frontends/tipsy/io.py
+++ b/yt/frontends/tipsy/io.py
@@ -58,7 +58,10 @@ def _fill_fields(self, fields, vals, hsml, mask, data_file):
         if mask is None:
             size = 0
         elif isinstance(mask, slice):
-            size = vals[fields[0]].size
+            if fields[0] == "smoothing_length":
+                size = hsml.size
+            else:
+                size = vals[fields[0]].size
         else:
             size = mask.sum()
         rv = {}
diff --git a/yt/frontends/tipsy/tests/test_outputs.py b/yt/frontends/tipsy/tests/test_outputs.py
index 7b7667b21f..73e8d6201b 100644
--- a/yt/frontends/tipsy/tests/test_outputs.py
+++ b/yt/frontends/tipsy/tests/test_outputs.py
@@ -112,3 +112,9 @@ def test_tipsy_index():
     ds = data_dir_load(tipsy_gal)
     sl = ds.slice("z", 0.0)
     assert sl["gas", "density"].shape[0] != 0
+
+
+@requires_file(tipsy_gal)
+def test_tipsy_smoothing_length():
+    ds = data_dir_load(tipsy_gal)
+    _ = ds.all_data()["Gas", "smoothing_length"]