From a78ac8fe237fd0b96bef73e03c874bac42b70ed4 Mon Sep 17 00:00:00 2001
From: Chris Kuehl <ckuehl@ocf.berkeley.edu>
Date: Tue, 29 Sep 2015 10:33:26 -0700
Subject: [PATCH 1/3] Exit nonzero if exec fails

---
 dumb-init.c                   | 10 ++++++++++
 tests/child_processes_test.py | 11 +++++++++++
 tox.ini                       |  7 +++++++
 3 files changed, 28 insertions(+)

diff --git a/dumb-init.c b/dumb-init.c
index febd4b8..d8093d0 100644
--- a/dumb-init.c
+++ b/dumb-init.c
@@ -128,6 +128,16 @@ int main(int argc, char *argv[]) {
         }
 
         execvp(argv[1], &argv[1]);
+
+        // if this point is reached, exec failed, so we should exit nonzero
+        fprintf(
+            stderr,
+            "Failed to launch process '%s' (errno %d: %s)\n",
+            argv[1],
+            errno,
+            strerror(errno)
+        );
+        exit(2);
     } else {
         pid_t killed_pid;
         int exit_status, status;
diff --git a/tests/child_processes_test.py b/tests/child_processes_test.py
index 5e2d686..3d28467 100644
--- a/tests/child_processes_test.py
+++ b/tests/child_processes_test.py
@@ -123,3 +123,14 @@ def test_processes_dont_receive_term_on_exit_if_no_setsid(
         assert child_stdout.readline() == str(signum).encode('ascii') + b'\n'
 
     os.kill(child_pid, signal.SIGKILL)
+
+
+def test_fails_nonzero_with_bad_exec(both_debug_modes, both_setsid_modes):
+    """If dumb-init can't exec as requested, it should exit nonzero."""
+    proc = Popen(('dumb-init', '/doesnotexist'), stderr=PIPE)
+    proc.wait()
+    assert proc.returncode != 0
+    assert (
+        "Failed to launch process '/doesnotexist' (errno 2: No such file or directory)\n"
+        in proc.stderr
+    )
diff --git a/tox.ini b/tox.ini
index 8f94ee6..26a65b3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,3 +9,10 @@ commands =
 
 [testenv:pre-commit]
 commands = pre-commit {posargs}
+
+[flake8]
+max-line-length = 119
+
+[pep8]
+# autopep8 will rewrite lines to be shorter, even though we raised the length
+ignore = E501

From d178fbaf525630913646683ee32b618358765e3b Mon Sep 17 00:00:00 2001
From: Chris Kuehl <ckuehl@ocf.berkeley.edu>
Date: Tue, 29 Sep 2015 10:49:08 -0700
Subject: [PATCH 2/3] Print better error message when exec fails

---
 dumb-init.c                   | 3 +--
 tests/child_processes_test.py | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/dumb-init.c b/dumb-init.c
index d8093d0..ed9de6b 100644
--- a/dumb-init.c
+++ b/dumb-init.c
@@ -132,9 +132,8 @@ int main(int argc, char *argv[]) {
         // if this point is reached, exec failed, so we should exit nonzero
         fprintf(
             stderr,
-            "Failed to launch process '%s' (errno %d: %s)\n",
+            "dumb-init: %s: %s\n",
             argv[1],
-            errno,
             strerror(errno)
         );
         exit(2);
diff --git a/tests/child_processes_test.py b/tests/child_processes_test.py
index 3d28467..df27625 100644
--- a/tests/child_processes_test.py
+++ b/tests/child_processes_test.py
@@ -131,6 +131,6 @@ def test_fails_nonzero_with_bad_exec(both_debug_modes, both_setsid_modes):
     proc.wait()
     assert proc.returncode != 0
     assert (
-        "Failed to launch process '/doesnotexist' (errno 2: No such file or directory)\n"
+        'dumb-init: /doesnotexist: No such file or directory\n'
         in proc.stderr
     )

From dd361496d17910a995f1986a901340d73cfa36af Mon Sep 17 00:00:00 2001
From: Chris Kuehl <ckuehl@ocf.berkeley.edu>
Date: Tue, 29 Sep 2015 10:50:49 -0700
Subject: [PATCH 3/3] tests/child_processes_test: fix py34

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

diff --git a/tests/child_processes_test.py b/tests/child_processes_test.py
index df27625..315795a 100644
--- a/tests/child_processes_test.py
+++ b/tests/child_processes_test.py
@@ -131,6 +131,6 @@ def test_fails_nonzero_with_bad_exec(both_debug_modes, both_setsid_modes):
     proc.wait()
     assert proc.returncode != 0
     assert (
-        'dumb-init: /doesnotexist: No such file or directory\n'
+        b'dumb-init: /doesnotexist: No such file or directory\n'
         in proc.stderr
     )