Stop leaking of filehandles to child processes by closing on fork.

Note: The close on fork bit you can set with ioctl isn't thread safe,
and only linux allows you to set it on open

1 files changed, 9 insertions, 2 deletions

diff --git a/src/engine/SCons/Platform/posix.py b/src/engine/SCons/Platform/posix.py
index ece48d7..3da1be7 100644
--- a/src/engine/SCons/Platform/posix.py
+++ b/src/engine/SCons/Platform/posix.py
@@ -47,6 +47,11 @@ exitvalmap = {
     13 : 126,
 }
 
+try:
+    MAXFD = os.sysconf("SC_OPEN_MAX")
+except:
+    MAXFD = 256
+
 def escape(arg):
     "escape shell special characters"
     slash = '\\'
@@ -70,11 +75,12 @@ def exec_spawnvpe(l, env):
     # returned by os.waitpid() or os.system().
     return stat
 
-def exec_fork(l, env): 
+def exec_fork(l, env):
     pid = os.fork()
     if not pid:
         # Child process.
         exitval = 127
+        os.closerange(3, MAXFD)
         try:
             os.execvpe(l[0], l, env)
         except OSError, e:
@@ -161,6 +167,7 @@ def exec_piped_fork(l, env, stdout, stderr):
         os.close( wFdOut )
         if stdout != stderr:
             os.close( wFdErr )
+        os.closerange(3, MAXFD)
         exitval = 127
         try:
             os.execvpe(l[0], l, env)
@@ -205,7 +212,7 @@ def piped_fork_spawn(sh, escape, cmd, args, env, stdout, stderr):
 def generate(env):
     # If os.spawnvpe() exists, we use it to spawn commands.  Otherwise
     # if the env utility exists, we use os.system() to spawn commands,
-    # finally we fall back on os.fork()/os.exec().  
+    # finally we fall back on os.fork()/os.exec().
     #
     # os.spawnvpe() is prefered because it is the most efficient.  But
     # for Python versions without it, os.system() is prefered because it