From def63f4608953392ecf6d86e0192a5d1526de5bb Mon Sep 17 00:00:00 2001
From: Tomoto Shimizu Washio <tomoto@gmail.com>
Date: Sun, 8 Dec 2024 23:16:07 +0900
Subject: [PATCH 1/3] fix: catch RecursionError in initialization

---
 fortls/langserver.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fortls/langserver.py b/fortls/langserver.py
index b6a1982e..d6aa6acb 100644
--- a/fortls/langserver.py
+++ b/fortls/langserver.py
@@ -1489,7 +1489,10 @@ def workspace_init(self):
         pool.close()
         pool.join()
         for path, result in results.items():
-            result_obj = result.get()
+            try:
+                result_obj = result.get()
+            except:
+                result_obj = traceback.format_exc()
             if isinstance(result_obj, str):
                 self.post_message(
                     f"Initialization failed for file {path}: {result_obj}"

From 800cc9c0392903c3ab2349d6c6940fe68efdd39e Mon Sep 17 00:00:00 2001
From: gnikit <giannis.nikiteas@gmail.com>
Date: Sat, 1 Mar 2025 22:33:47 +0000
Subject: [PATCH 2/3] feat: improve Exception handling

multiprocessing.Pool does not retain the base exception
that caused it to raise.
As a result it is not possible under this setup
to explicitly capture the RecursionError that is
getting raised when Pool attempts to pickle
the AST from the parser.
---
 fortls/langserver.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fortls/langserver.py b/fortls/langserver.py
index d6aa6acb..c11f60c4 100644
--- a/fortls/langserver.py
+++ b/fortls/langserver.py
@@ -1491,8 +1491,12 @@ def workspace_init(self):
         for path, result in results.items():
             try:
                 result_obj = result.get()
-            except:
-                result_obj = traceback.format_exc()
+            except Exception as e:
+                result_obj = (
+                    "An exception has occured while initialising the workspace.\n"
+                    f"Exception({(type(e))}): {e}\n"
+                    + f"Traceback: {traceback.format_exc()}"
+                )
             if isinstance(result_obj, str):
                 self.post_message(
                     f"Initialization failed for file {path}: {result_obj}"

From f00b8ea5625334e96d34881b07884d2ee9c0d4f5 Mon Sep 17 00:00:00 2001
From: gnikit <giannis.nikiteas@gmail.com>
Date: Sat, 1 Mar 2025 22:34:48 +0000
Subject: [PATCH 3/3] test: add unit test that specifically checks the
 workspace_init exception handling mechanism

---
 test/test_server_init.py | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 test/test_server_init.py

diff --git a/test/test_server_init.py b/test/test_server_init.py
new file mode 100644
index 00000000..9573f498
--- /dev/null
+++ b/test/test_server_init.py
@@ -0,0 +1,32 @@
+import os
+import tempfile
+
+import pytest
+from setup_tests import Path, run_request, write_rpc_request
+
+from fortls.constants import Severity
+
+
+@pytest.fixture()
+def setup_tmp_file():
+    levels = 2000
+    fd, filename = tempfile.mkstemp(suffix=".f90")
+    try:
+        with os.fdopen(fd, "w") as tmp:
+            tmp.write(
+                "program nested_if\n"
+                + str("if (.true.) then\n" * levels)
+                + str("end if\n" * levels)
+                + "end program nested_if"
+            )
+        yield filename
+    finally:
+        os.remove(filename)
+
+
+def test_recursion_error_handling(setup_tmp_file):
+    root = Path(setup_tmp_file).parent
+    request_string = write_rpc_request(1, "initialize", {"rootPath": str(root)})
+    errcode, results = run_request(request_string)
+    assert errcode == 0
+    assert results[0]["type"] == Severity.error