Fix delegator leaky file handles

Signed-off-by: Dan Ryan <dan@danryan.co>

pipenv/vendor/delegator.py

@@ -178,6 +178,7 @@ class Command(object):
         # Use subprocess.
         if self.blocking:
             popen_kwargs = self._default_popen_kwargs.copy()
+            del popen_kwargs["stdin"]
             popen_kwargs["universal_newlines"] = not binary
             if cwd:
                 popen_kwargs["cwd"] = cwd
@@ -234,14 +235,22 @@ class Command(object):
         """Blocks until process is complete."""
         if self._uses_subprocess:
             # consume stdout and stderr
-            try:
-                stdout, stderr = self.subprocess.communicate()
-                self.__out = stdout
-                self.__err = stderr
-            except ValueError:
-                pass  # Don't read from finished subprocesses.
+            if self.blocking:
+                try:
+                    stdout, stderr = self.subprocess.communicate()
+                    self.__out = stdout
+                    self.__err = stderr
+                except ValueError:
+                    pass  # Don't read from finished subprocesses.
+            else:
+                self.subprocess.stdin.close()
+                self.std_out.close()
+                self.std_err.close()
+                self.subprocess.wait()
         else:
+            self.subprocess.sendeof()
             self.subprocess.wait()
+            self.subprocess.proc.stdout.close()
 
     def pipe(self, command, timeout=None, cwd=None):
         """Runs the current command and passes its output to the next

tasks/vendoring/patches/vendor/delegator-close-filehandles.patch

@@ -0,0 +1,44 @@
+diff --git a/pipenv/vendor/delegator.py b/pipenv/vendor/delegator.py
+index 0c140cad..3ffb2e31 100644
+--- a/pipenv/vendor/delegator.py
++++ b/pipenv/vendor/delegator.py
+@@ -178,6 +178,7 @@ class Command(object):
+         # Use subprocess.
+         if self.blocking:
+             popen_kwargs = self._default_popen_kwargs.copy()
++            del popen_kwargs["stdin"]
+             popen_kwargs["universal_newlines"] = not binary
+             if cwd:
+                 popen_kwargs["cwd"] = cwd
+@@ -233,18 +234,23 @@ class Command(object):
+     def block(self):
+         """Blocks until process is complete."""
+         if self._uses_subprocess:
+-            self.subprocess.stdin.close()
+             # consume stdout and stderr
+-            try:
+-                stdout, stderr = self.subprocess.communicate()
+-                self.__out = stdout
+-                self.__err = stderr
+-            except ValueError:
+-                pass  # Don't read from finished subprocesses.
++            if self.blocking:
++                try:
++                    stdout, stderr = self.subprocess.communicate()
++                    self.__out = stdout
++                    self.__err = stderr
++                except ValueError:
++                    pass  # Don't read from finished subprocesses.
++            else:
++                self.subprocess.stdin.close()
++                self.std_out.close()
++                self.std_err.close()
++                self.subprocess.wait()
+         else:
+             self.subprocess.sendeof()
+-            self.subprocess.proc.stdout.close()
+             self.subprocess.wait()
++            self.subprocess.proc.stdout.close()
+ 
+     def pipe(self, command, timeout=None, cwd=None):
+         """Runs the current command and passes its output to the next