From 1143f0987cc0843eb95179b549943041adeebfd5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kl=C3=B6tzke?= <jan@kloetzke.net>
Date: Sat, 27 Dec 2025 16:41:39 +0100
Subject: [PATCH 1/2] url: handle OSError on download

Reading from the socket might cause an OSError (e.g.
"ConnectionResetError: [Errno 104] Connection reset by peer"). We must
catch such errors and gracefully handle them in the retry loop. On the
other hand, writing to the local file can cause OSError exceptions too.
This should not happen but in case of "disk full" errors, we can
probably stop retrying.

Fixes #685.
---
 pym/bob/scm/url.py | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/pym/bob/scm/url.py b/pym/bob/scm/url.py
index d1d9111a..d95b254f 100644
--- a/pym/bob/scm/url.py
+++ b/pym/bob/scm/url.py
@@ -12,6 +12,7 @@
 from http.client import HTTPException
 from abc import abstractmethod
 import asyncio
+import errno
 import concurrent.futures.process
 import contextlib
 import hashlib
@@ -512,7 +513,7 @@ def _download(self, url, destination, mode):
                 if "content-length" in rsp.info():
                     expected = int(rsp.info()["Content-Length"])
                     if expected > read:
-                        return False, "Response too short: {} < {} (bytes)".format(read, expected)
+                        return False, "Response too short: {} < {} (bytes)".format(read, expected), False
 
                 # Atomically move file to destination. Set mode to 0600 to
                 # retain Bob 0.15 behaviour if no explicit mode was configured.
@@ -522,12 +523,14 @@ def _download(self, url, destination, mode):
 
         except urllib.error.HTTPError as e:
             if e.code != 304:
-                return False, "HTTP error {}: {}".format(e.code, e.reason)
+                return False, "HTTP error {}: {}".format(e.code, e.reason), False
             else:
                 # HTTP 304 Not modifed -> local file up-to-date
-                return False, None
+                return False, None, False
         except HTTPException as e:
-            return False, "HTTP error: " + str(e)
+            return False, "HTTP error: " + str(e), False
+        except OSError as e:
+            return False, "Failed to download: " + str(e), e.errno == errno.ENOSPC
         finally:
             if tmpFileName is not None:
                 os.remove(tmpFileName)
@@ -535,7 +538,7 @@ def _download(self, url, destination, mode):
             # to prevent ugly backtraces when user presses ctrl+c.
             signal.signal(signal.SIGINT, signal.SIG_DFL)
 
-        return True, None
+        return True, None, False
 
     async def _fetch(self, invoker, url, destination, mode):
         if url.scheme in ['', 'file']:
@@ -565,9 +568,11 @@ async def _fetch(self, invoker, url, destination, mode):
             while True:
                 invoker.trace("<wget>", url.geturl(), ">", destination, "retires:", retries)
                 try:
-                    updated, err = await invoker.runInExecutor(UrlScm._download, self, url, destination, mode)
+                    updated, err, fatal = await invoker.runInExecutor(UrlScm._download, self, url, destination, mode)
                     if err:
-                        if retries == 0:
+                        if fatal:
+                            invoker.fail(err)
+                        elif retries == 0:
                             return False, err
                         else:
                             invoker.warn(err)

From f1913a7c8eae67359b4f967cdb6dd2002f17e0c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Kl=C3=B6tzke?= <jan@kloetzke.net>
Date: Sat, 27 Dec 2025 16:50:45 +0100
Subject: [PATCH 2/2] test: test disk full errors in url scm

---
 test/unit/test_input_urlscm.py | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/test/unit/test_input_urlscm.py b/test/unit/test_input_urlscm.py
index a2957c00..475eece2 100644
--- a/test/unit/test_input_urlscm.py
+++ b/test/unit/test_input_urlscm.py
@@ -7,6 +7,9 @@
 from unittest import TestCase, skipIf
 from unittest.mock import MagicMock, patch
 import asyncio
+import contextlib
+import errno
+import concurrent.futures
 import os, stat
 import subprocess
 import shutil
@@ -54,8 +57,9 @@ def __exit__(self, exception_type, exception_value, exception_traceback):
 
 class UrlScmExecutor:
 
-    def invokeScm(self, workspace, scm, switch=False, oldScm=None, workspaceCreated=False):
-        executor = getProcessPoolExecutor()
+    def invokeScm(self, workspace, scm, switch=False, oldScm=None, workspaceCreated=False, executor=None):
+        if executor is None:
+            executor = getProcessPoolExecutor()
         try:
             spec = MagicMock(workspaceWorkspacePath=workspace, envWhiteList=set())
             invoker = Invoker(spec, False, True, True, True, True, False,
@@ -341,6 +345,27 @@ def testNoResponse(self):
                 with self.assertRaises(InvocationError):
                     self.invokeScm(workspace, scm)
 
+    @patch('signal.signal')
+    def testDownloadDiskFull(self, signalMock):
+        """Full disk directly terminates downloads"""
+        tmp = MagicMock()
+        tmp.name = None
+        tmp.write.side_effect = OSError(errno.ENOSPC, "Disk full")
+        ntf = MagicMock(return_value=contextlib.nullcontext(enter_result=tmp))
+
+        with (HttpServerMock(self.dir)  as srv,
+              TemporaryWorkspace()      as workspace,
+              patch('tempfile.NamedTemporaryFile', ntf)):
+            scm = self.createUrlScm({
+                "url" : "http://localhost:{}/test.txt".format(srv.port),
+                "retries" : 3
+            })
+
+            with self.assertRaises(InvocationError):
+                self.invokeScm(workspace, scm, executor=concurrent.futures.ThreadPoolExecutor())
+
+            self.assertEqual(srv.getRequests, 1, "URL SCM does not retry on disk full errors")
+
 class TestExtraction(TestCase):
 
     @classmethod