From: Zac Medico <zmedico@gentoo.org>
Date: Tue, 15 Jan 2013 14:12:27 +0000 (-0800)
Subject: SpawnProcess: avoid fd_pipes interference
X-Git-Tag: v2.2.0_alpha153~3
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=04f8dfb158bcadc1017a64e9fad5e744d4f91f9c;p=portage.git

SpawnProcess: avoid fd_pipes interference

This fixes a random collision that can occur with FileDigester,
triggering malfunction and a KeyError.
---

diff --git a/pym/_emerge/SpawnProcess.py b/pym/_emerge/SpawnProcess.py
index 5d0fcf6dd..9c754add5 100644
--- a/pym/_emerge/SpawnProcess.py
+++ b/pym/_emerge/SpawnProcess.py
@@ -76,8 +76,14 @@ class SpawnProcess(SubProcess):
 
 		else:
 			# Create a dummy pipe so the scheduler can monitor
-			# the process from inside a poll() loop.
-			fd_pipes[self._dummy_pipe_fd] = slave_fd
+			# the process from inside a poll() loop. Ensure that
+			# it doesn't interfere with a random fd that's already
+			# in fd_pipes though (as least FileDigester can pass
+			# in a random fd returned from os.pipe()).
+			unique_dummy_fd = self._dummy_pipe_fd
+			while unique_dummy_fd in fd_pipes:
+				unique_dummy_fd += 1
+			fd_pipes[unique_dummy_fd] = slave_fd
 			if self.background:
 				fd_pipes[1] = slave_fd
 				fd_pipes[2] = slave_fd