From 16a99487590b6b19dc06569f18ffadc70c78dcf3 Mon Sep 17 00:00:00 2001
From: George Edward Bulmer <gebulmer@googlemail.com>
Date: Tue, 12 Dec 2017 22:23:33 +0000
Subject: [PATCH 1/3] Replace malformed utf-8 characters in spawn output.

Previously this simply crashed if there was ever malformed utf-8 in the
stderr or stdout streams, perhaps as a result of an incorrectly spawned
command. See e.g. #3222
---
 qutebrowser/misc/guiprocess.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/qutebrowser/misc/guiprocess.py b/qutebrowser/misc/guiprocess.py
index 4fb887de0..a0a8ad639 100644
--- a/qutebrowser/misc/guiprocess.py
+++ b/qutebrowser/misc/guiprocess.py
@@ -98,8 +98,10 @@ class GUIProcess(QObject):
         log.procs.debug("Process finished with code {}, status {}.".format(
             code, status))
 
-        stderr = bytes(self._proc.readAllStandardError()).decode('utf-8')
-        stdout = bytes(self._proc.readAllStandardOutput()).decode('utf-8')
+        stderr = bytes(self._proc.readAllStandardError()).decode('utf-8',
+                                                                 'replace')
+        stdout = bytes(self._proc.readAllStandardOutput()).decode('utf-8',
+                                                                  'replace')
 
         qutescheme.spawn_output = self._spawn_format(code, status,
                                                      stdout, stderr)

From 28961ab177d9d70109b58f9dc741232328d089c3 Mon Sep 17 00:00:00 2001
From: George Edward Bulmer <gebulmer@googlemail.com>
Date: Wed, 13 Dec 2017 12:46:46 +0000
Subject: [PATCH 2/3] Add a test with invalid unicode in spawned stdout.

stderr features identical behaviour, so is currently untested.
---
 tests/unit/misc/test_guiprocess.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tests/unit/misc/test_guiprocess.py b/tests/unit/misc/test_guiprocess.py
index 25e46476e..473016b52 100644
--- a/tests/unit/misc/test_guiprocess.py
+++ b/tests/unit/misc/test_guiprocess.py
@@ -63,6 +63,20 @@ def test_start(proc, qtbot, message_mock, py_proc):
     assert qutescheme.spawn_output == proc._spawn_format(stdout="test")
 
 
+def test_stdout_malformed_utf8(proc, qtbot, message_mock, py_proc):
+    """Test simply starting a process."""
+    with qtbot.waitSignals([proc.started, proc.finished], timeout=10000,
+                           order='strict'):
+        argv = py_proc(r"""
+            import sys
+            sys.stdout.buffer.write(b"A\x80B")
+            sys.exit(0)
+            """)
+        proc.start(*argv)
+    assert not message_mock.messages
+    assert qutescheme.spawn_output == proc._spawn_format(stdout="A\ufffdB")
+
+
 def test_start_verbose(proc, qtbot, message_mock, py_proc):
     """Test starting a process verbosely."""
     proc.verbose = True

From 84e0ce757ad3c4460b7394f3a321ae1ebc0e660c Mon Sep 17 00:00:00 2001
From: George Edward Bulmer <gebulmer@googlemail.com>
Date: Wed, 13 Dec 2017 14:50:25 +0000
Subject: [PATCH 3/3] Fix erroneous docstring in a recently added test.

---
 tests/unit/misc/test_guiprocess.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/unit/misc/test_guiprocess.py b/tests/unit/misc/test_guiprocess.py
index 473016b52..b74b0383a 100644
--- a/tests/unit/misc/test_guiprocess.py
+++ b/tests/unit/misc/test_guiprocess.py
@@ -64,7 +64,7 @@ def test_start(proc, qtbot, message_mock, py_proc):
 
 
 def test_stdout_malformed_utf8(proc, qtbot, message_mock, py_proc):
-    """Test simply starting a process."""
+    """Test handling malformed utf-8 in stdout."""
     with qtbot.waitSignals([proc.started, proc.finished], timeout=10000,
                            order='strict'):
         argv = py_proc(r"""