From 35ecf36b6816cd76bd56c1e8f76fa845baa96a5b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20Zim=C3=A1nyi?= <estebanzimanyi@gmail.com>
Date: Sat, 31 Oct 2026 15:15:39 +0100
Subject: [PATCH] Set the date and interval styles of pymeos_initialize from
 their names

pymeos_initialize sets a date style or an interval style given by name
through meos_set_datestyle and meos_set_intervalstyle, passing each the
null value its extra parameter takes in C: _ffi.NULL for the void
pointer of meos_set_datestyle and 0 for the int of
meos_set_intervalstyle. MEOS overwrites extra with the style it parses
from the name, so the value passed is never read.

tests/meos_init_test.py sets each date style and interval style by name
and reads it back with meos_get_datestyle and meos_get_intervalstyle,
restoring the styles conftest initializes after each case.
---
 pymeos/meos_init.py     |  5 +++--
 tests/meos_init_test.py | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 tests/meos_init_test.py

diff --git a/pymeos/meos_init.py b/pymeos/meos_init.py
index d2884852..6508206c 100644
--- a/pymeos/meos_init.py
+++ b/pymeos/meos_init.py
@@ -6,6 +6,7 @@
     meos_set_datestyle,
     meos_set_intervalstyle,
 )
+from pymeos_cffi.functions import _ffi
 
 
 def pymeos_initialize(
@@ -29,13 +30,13 @@ def pymeos_initialize(
 
     if date_style is not None:
         if isinstance(date_style, str):
-            meos_set_datestyle(date_style, None)
+            meos_set_datestyle(date_style, _ffi.NULL)
         else:
             meos_set_datestyle(*date_style)
 
     if interval_style is not None:
         if isinstance(interval_style, str):
-            meos_set_intervalstyle(interval_style, None)
+            meos_set_intervalstyle(interval_style, 0)
         else:
             meos_set_intervalstyle(*interval_style)
 
diff --git a/tests/meos_init_test.py b/tests/meos_init_test.py
new file mode 100644
index 00000000..829aac13
--- /dev/null
+++ b/tests/meos_init_test.py
@@ -0,0 +1,38 @@
+import pytest
+from pymeos_cffi import meos_get_datestyle, meos_get_intervalstyle
+
+from pymeos import pymeos_initialize
+from tests.conftest import TestPyMEOS
+
+
+# Laid out as #TestTInterpolation; each test restores the styles it changes, since
+# every other test runs under the styles conftest initializes.
+class TestPyMEOSInitialize(TestPyMEOS):
+    @pytest.mark.parametrize(
+        "date_style, expected",
+        [
+            ("SQL, DMY", "SQL, DMY"),
+            ("German", "German, DMY"),
+            ("Postgres, MDY", "Postgres, MDY"),
+        ],
+        ids=["SQL DMY", "German", "Postgres MDY"],
+    )
+    def test_date_style(self, date_style, expected):
+        previous = meos_get_datestyle()
+        try:
+            pymeos_initialize("UTC", date_style=date_style)
+            assert meos_get_datestyle() == expected
+        finally:
+            pymeos_initialize("UTC", date_style=previous)
+
+    @pytest.mark.parametrize(
+        "interval_style",
+        ["postgres", "postgres_verbose", "sql_standard", "iso_8601"],
+    )
+    def test_interval_style(self, interval_style):
+        previous = meos_get_intervalstyle()
+        try:
+            pymeos_initialize("UTC", interval_style=interval_style)
+            assert meos_get_intervalstyle() == interval_style
+        finally:
+            pymeos_initialize("UTC", interval_style=previous)