From f14166517af9ec75fc96489e4998946d4570ea3c Mon Sep 17 00:00:00 2001
From: Vincent Favre-Nicolin <vincent.favre-nicolin@esrf.fr>
Date: Tue, 28 Jul 2026 13:30:09 +0200
Subject: [PATCH] Fix displ_transl refinement toggle in quick_fit_profile

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
---
 news/83.rst                     | 23 +++++++++++++++++++
 src/pyobjcryst/powderpattern.py |  4 ++--
 tests/test_powderpattern.py     | 39 +++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 2 deletions(-)
 create mode 100644 news/83.rst

diff --git a/news/83.rst b/news/83.rst
new file mode 100644
index 0000000..57ea1e8
--- /dev/null
+++ b/news/83.rst
@@ -0,0 +1,23 @@
+**Added:**
+
+* None.
+
+**Changed:**
+
+* None.
+
+**Deprecated:**
+
+* None.
+
+**Removed:**
+
+* None.
+
+**Fixed:**
+
+* `quick_fit_profile(displ_transl=True)` now correctly enables refinement of `2ThetaDispl` and `2ThetaTransp` by unfixing both parameters.
+
+**Security:**
+
+* None.
diff --git a/src/pyobjcryst/powderpattern.py b/src/pyobjcryst/powderpattern.py
index f930482..2803693 100644
--- a/src/pyobjcryst/powderpattern.py
+++ b/src/pyobjcryst/powderpattern.py
@@ -425,8 +425,8 @@ def quick_fit_profile(
         if zero:
             lsq.SetParIsFixed("Zero", False)
         if displ_transl:
-            lsq.SetParIsFixed("2ThetaDispl", True)
-            lsq.SetParIsFixed("2ThetaTransp", True)
+            lsq.SetParIsFixed("2ThetaDispl", False)
+            lsq.SetParIsFixed("2ThetaTransp", False)
         if lsqr.GetNbParNotFixed():
             lsq.SafeRefine(nbCycle=10, useLevenbergMarquardt=True, silent=True)
             pdiff.ExtractLeBail(10)
diff --git a/tests/test_powderpattern.py b/tests/test_powderpattern.py
index 7acb666..5efb1f6 100644
--- a/tests/test_powderpattern.py
+++ b/tests/test_powderpattern.py
@@ -15,6 +15,7 @@
 """Unit tests for pyobjcryst.powderpattern (with indexing &"""
 
 import unittest
+from unittest.mock import MagicMock, patch
 
 import numpy as np
 import pytest
@@ -185,6 +186,44 @@ def test_quick_fit(self):
         p.SetMaxSinThetaOvLambda(0.3)
         p.quick_fit_profile(auto_background=True, verbose=False, plot=False)
 
+    def test_quick_fit_profile_displ_transl_unfixes_refinement_parameters(
+        self,
+    ):
+        fake_powder_pattern = MagicMock()
+        fake_diffraction = MagicMock()
+        fake_lsqr = MagicMock()
+        fake_lsqr.GetNbParNotFixed.return_value = 0
+        fake_lsq = MagicMock()
+        fake_lsq.GetCompiledRefinedObj.return_value = fake_lsqr
+
+        with patch("pyobjcryst.powderpattern.LSQ", return_value=fake_lsq):
+            PowderPattern.quick_fit_profile(
+                fake_powder_pattern,
+                pdiff=fake_diffraction,
+                auto_background=False,
+                init_profile=False,
+                plot=False,
+                zero=False,
+                constant_width=False,
+                width=False,
+                eta=False,
+                cell=False,
+                asym=False,
+                backgd=False,
+                displ_transl=True,
+                verbose=False,
+            )
+
+        displ_transl_calls = [
+            call.args
+            for call in fake_lsq.SetParIsFixed.call_args_list
+            if call.args[0] in ("2ThetaDispl", "2ThetaTransp")
+        ]
+        self.assertEqual(
+            displ_transl_calls,
+            [("2ThetaDispl", False), ("2ThetaTransp", False)],
+        )
+
     def test_peaklist_index(self):
         c = self.loadcifdata("paracetamol.cif")
         p = PowderPattern()