From 9ab77dee4248ec1013150e5dd2518ef086c5d837 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Ko=C5=88a=C5=99=C3=ADk?= <dvdkon@konarici.cz>
Date: Wed, 17 Dec 2025 17:12:45 +0100
Subject: [PATCH 1/2] Change MerginProject constructor to force one instance
 per project

---
 mergin/merginproject.py | 26 +++++++++++++++++++++++++-
 setup.py                |  2 +-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/mergin/merginproject.py b/mergin/merginproject.py
index 9013651..0b9bf13 100644
--- a/mergin/merginproject.py
+++ b/mergin/merginproject.py
@@ -4,8 +4,9 @@
 import os
 import re
 import shutil
-import uuid
 import tempfile
+import uuid
+import weakref
 from datetime import datetime
 from dateutil.tz import tzlocal
 
@@ -41,7 +42,30 @@ class MerginProject:
     Linked to existing local directory, with project metadata (mergin.json) and backups located in .mergin directory.
     """
 
+    # To make sure we don't have multiple instances for a single project that
+    # then have out-of-date information, we keep this map of absolute project
+    # directory paths to instances.
+    # The dictionary is a WeakValueDictionary so we don't cause memory leaks
+    # (when the instance is GC'd, the entry is deleted).
+    project_cache: weakref.WeakValueDictionary[str, "MerginProject"] = weakref.WeakValueDictionary()
+
+    def __new__(cls, directory):
+        directory = os.path.abspath(directory)
+        if instance := cls.project_cache.get(directory):
+            return instance
+
+        instance = super().__new__(cls)
+        cls.project_cache[directory] = instance
+        return instance
+
     def __init__(self, directory):
+        # __init__ still gets called after __new__, even if it returns a
+        # pre-existing object. Work around this by checking whether we've been
+        # initialised.
+        if hasattr(self, "_initialised"):
+            return
+        self._initialised = True
+
         self.dir = os.path.abspath(directory)
         if not os.path.exists(self.dir):
             raise InvalidProject("Project directory does not exist")
diff --git a/setup.py b/setup.py
index da2d05a..a8184e6 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@
 
 setup(
     name="mergin-client",
-    version="0.11.0",
+    version="0.12.0",
     url="https://github.com/MerginMaps/python-api-client",
     license="MIT",
     author="Lutra Consulting Ltd.",

From f4a3cf67e7141e227b8ac691896ff4fc3992edbd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Ko=C5=88a=C5=99=C3=ADk?= <dvdkon@konarici.cz>
Date: Fri, 19 Dec 2025 11:55:32 +0100
Subject: [PATCH 2/2] Apply changes from review

---
 mergin/merginproject.py | 11 ++++++-----
 setup.py                |  2 +-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/mergin/merginproject.py b/mergin/merginproject.py
index 0b9bf13..fc3d5a7 100644
--- a/mergin/merginproject.py
+++ b/mergin/merginproject.py
@@ -51,12 +51,13 @@ class MerginProject:
 
     def __new__(cls, directory):
         directory = os.path.abspath(directory)
-        if instance := cls.project_cache.get(directory):
+        instance = cls.project_cache.get(directory)
+        if instance:
+            return instance
+        else:
+            instance = super().__new__(cls)
+            cls.project_cache[directory] = instance
             return instance
-
-        instance = super().__new__(cls)
-        cls.project_cache[directory] = instance
-        return instance
 
     def __init__(self, directory):
         # __init__ still gets called after __new__, even if it returns a
diff --git a/setup.py b/setup.py
index a8184e6..da2d05a 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@
 
 setup(
     name="mergin-client",
-    version="0.12.0",
+    version="0.11.0",
     url="https://github.com/MerginMaps/python-api-client",
     license="MIT",
     author="Lutra Consulting Ltd.",