lib: don't try to drain the buffer on an unreleased process

Depending on where we're at in the closing of the process, we could easily
catch a SIGPIPE here if we, e.g., sent a SIGINT and killed the process.

Coincidentally, stop spawning a cat(1) process that we won't be using for
the resize tests.  The implicit close from immediately spawning off the
shell script tripped over this drain error intermittently.

Signed-off-by: Kyle Evans <[email protected]>

lib/porch/process.lua

@@ -204,9 +204,15 @@ function Process:write(data, cfg)
 end
 function Process:close()
 	local function procdrain()
-		if not self.buffer.eof then
-			self.buffer:refill()
+		-- It's imperative that we not try to drain a process that
+		-- hasn't been started yet; there won't be anything pending
+		-- anyways, and trying to release it may end up catching us a
+		-- SIGPIPE.
+		if self.buffer.eof or not self._process:released() then
+			return
 		end
+
+		self.buffer:refill()
 	end
 
 	assert(self._process:close(procdrain))

tests/basic_test.sh

@@ -69,7 +69,7 @@ for f in "$@" ;do
 			continue
 		fi
 		;;
-	spawn_*)
+	spawn_*|resize_*)
 		spawn=""
 		;;
 	esac