WIP

.github/workflows/tests.yml

@@ -25,12 +25,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - tox_env: py27-m_ans-ans2.10
-          - tox_env: py27-m_ans-ans4
-
-          - tox_env: py36-m_ans-ans2.10
-          - tox_env: py36-m_ans-ans4
-
           - tox_env: py27-m_mtg
           - tox_env: py36-m_mtg
 
@@ -86,34 +80,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - tox_env: py311-m_ans-ans2.10
-            python_version: '3.11'
-          - tox_env: py311-m_ans-ans3
-            python_version: '3.11'
-          - tox_env: py311-m_ans-ans4
-            python_version: '3.11'
-          - tox_env: py311-m_ans-ans5
-            python_version: '3.11'
-          - tox_env: py313-m_ans-ans6
-            python_version: '3.13'
-          - tox_env: py313-m_ans-ans7
-            python_version: '3.13'
-          - tox_env: py313-m_ans-ans8
-            python_version: '3.13'
-          - tox_env: py314-m_ans-ans9
-            python_version: '3.14'
-          - tox_env: py314-m_ans-ans10
-            python_version: '3.14'
-          - tox_env: py314-m_ans-ans11
-            python_version: '3.14'
-          - tox_env: py314-m_ans-ans12
-            python_version: '3.14'
-          - tox_env: py314-m_ans-ans13
-            python_version: '3.14'
-
-          - tox_env: py314-m_ans-ans13-s_lin
-            python_version: '3.14'
-
           - tox_env: py314-m_mtg
             python_version: '3.14'
 
@@ -161,11 +127,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - tox_env: py314-m_lcl-ans13
-            python_version: '3.14'
-          - tox_env: py314-m_lcl-ans13-s_lin
-            python_version: '3.14'
-
           - tox_env: py314-m_mtg
             python_version: '3.14'
 

mitogen/parent.py

@@ -1415,11 +1415,11 @@ class Connection(object):
     #   W: write side of interpreter stdin.
     #   r: read side of core_src FD.
     #   w: write side of core_src FD.
-
-    # Final os.close(STDOUT_FILENO) to avoid --py-debug build corrupting stream with
-    # "[1234 refs]" during exit.
     @staticmethod
     def _first_stage():
+        # Bail out in case STDIN or STDOUT is not accessible (e.g. closed)
+        #os.fstat(0)
+        #os.fstat(1)
         R,W=os.pipe()
         r,w=os.pipe()
         if os.fork():
@@ -1436,11 +1436,16 @@ class Connection(object):
             os.environ['ARGV0']=sys.executable
             os.execl(sys.executable,sys.executable+'(mitogen:%s)'%sys.argv[2])
         os.write(1,'MITO000\n'.encode())
+        # size of the compressed core source to be read
+        n=int(sys.argv[3])
         # Read `len(compressed preamble)` bytes sent by our Mitogen parent.
         # `select()` handles non-blocking stdin (e.g. sudo + log_output).
         # `C` accumulates compressed bytes.
         C=''.encode()
-        while int(sys.argv[3])-len(C)and select.select([0],[],[]):C+=os.read(0,int(sys.argv[3])-len(C))
+        # data chunk
+        V='V'
+        # Stop looping if no more data is needed or EOF is detected (empty bytes).
+        while n-len(C) and V:select.select([0],[],[]);V=os.read(0,n-len(C));C+=V
         # Raises `zlib.error` if compressed preamble is truncated or invalid
         C=zlib.decompress(C)
         f=os.fdopen(W,'wb',0)
@@ -1450,6 +1455,10 @@ class Connection(object):
         f.write(C)
         f.close()
         os.write(1,'MITO001\n'.encode())
+        # Final os.close(STDERR_FILENO) to avoid `--py-debug` build corrupting
+        # stream with "[1234 refs]" during exit.
+        # If STDERR is already closed an OSError is raised, but no one cares
+        # as STDERR is closed and the exit status is not forwarded.
         os.close(2)
 
     def get_python_argv(self):

tests/first_stage_test.py

@@ -50,3 +50,39 @@ class CommandLineTest(testlib.RouterMixin, testlib.TestCase):
             )
         finally:
             fp.close()
+
+    def test_premature_eof(self):
+        options = mitogen.parent.Options(max_message_size=123)
+        conn = mitogen.parent.Connection(options, self.router)
+        conn.context = mitogen.core.Context(None, 123)
+
+        proc = testlib.subprocess.Popen(
+            args=conn.get_boot_command(),
+            stdout=testlib.subprocess.PIPE,
+            stderr=testlib.subprocess.PIPE,
+            stdin=testlib.subprocess.PIPE,
+        )
+
+        # Do not send all of the data from the preamble
+        proc.stdin.write(conn.get_preamble()[:-128])
+        proc.stdin.flush()  # XXX Is this redundant? Does close() alwys flush()?
+        proc.stdin.close()
+        try:
+            returncode = proc.wait(timeout=10)
+        except testlib.subprocess.TimeoutExpired:
+            proc.kill()
+            proc.wait(timeout=3)
+            self.fail("First stage did not handle EOF on STDIN")
+        try:
+            self.assertEqual(0, returncode)
+            self.assertEqual(
+                proc.stdout.read(),
+                mitogen.parent.BootstrapProtocol.EC0_MARKER + b("\n"),
+            )
+            self.assertIn(
+                b("Error -5 while decompressing data"),
+                proc.stderr.read(),
+            )
+        finally:
+            proc.stdout.close()
+            proc.stderr.close()