From 910e31f0154734f5bdfaa2d334a037eeeead295b Mon Sep 17 00:00:00 2001
From: Corinna Vinschen <corinna@vinschen.de>
Date: Mon, 29 Nov 2010 20:51:38 +0000
Subject: [PATCH] 	* fhandler_tty.cc (fhandler_tty_slave::dup): Free
 path_conv strings 	to avoid memory leak.  Add comment. 
 (fhandler_pty_master::dup): Ditto. 	* path.h (path_conv::free_strings):
 New method.

---
 winsup/cygwin/ChangeLog       |  7 +++++++
 winsup/cygwin/fhandler_tty.cc | 14 ++++++++++++++
 winsup/cygwin/path.h          |  5 +++++
 3 files changed, 26 insertions(+)

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 4986faab9..5fcd5b8c9 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,10 @@
+2010-11-29  Corinna Vinschen  <corinna@vinschen.de>
+
+	* fhandler_tty.cc (fhandler_tty_slave::dup): Free path_conv strings
+	to avoid memory leak.  Add comment.
+	(fhandler_pty_master::dup): Ditto.
+	* path.h (path_conv::free_strings): New method.
+
 2010-11-23  Corinna Vinschen  <corinna@vinschen.de>
 
 	* autoload.cc (SendARP): Remove.
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 23a07d0b4..0c32d5311 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -979,6 +979,18 @@ int
 fhandler_tty_slave::dup (fhandler_base *child)
 {
   fhandler_tty_slave *arch = (fhandler_tty_slave *) archetype;
+  /* In dtable::dup_worker, the path_conv member has already been assigned
+     from "this" to "child".  Part of this assigment (path_conv::operator=)
+     is to allocate memory for the strings "path" and "normalized_path from
+     cygheap.  The below `child = *arch' statement will overwrite child's
+     path_conv again, this time from "*arch".  By doing that, it will allocate
+     new strings from cygheap, overwriting the old pointer values.  Thus, the
+     old allocated strings are lost, and we're leaking memory for each tty dup,
+     unless we free the strings here.
+     FIXME: We can't redefine path_conv::operator= so that it frees the old
+     strings.  Probably it would be most helpful to copy only the required
+     members from *arch, rather than copying everything. */
+  child->pc.free_strings ();
   *(fhandler_tty_slave *) child = *arch;
   child->set_flags (get_flags ());
   child->usecount = 0;
@@ -992,6 +1004,8 @@ int
 fhandler_pty_master::dup (fhandler_base *child)
 {
   fhandler_tty_master *arch = (fhandler_tty_master *) archetype;
+  /* See comment in fhandler_tty_slave::dup. */
+  child->pc.free_strings ();
   *(fhandler_tty_master *) child = *arch;
   child->set_flags (get_flags ());
   child->usecount = 0;
diff --git a/winsup/cygwin/path.h b/winsup/cygwin/path.h
index c5b10e3c7..ef6cac44e 100644
--- a/winsup/cygwin/path.h
+++ b/winsup/cygwin/path.h
@@ -293,6 +293,11 @@ class path_conv
     wide_path = NULL;
     return *this;
   }
+  void free_strings ()
+  {
+    cfree (modifiable_path ());
+    cfree ((char *) normalized_path);
+  }
   DWORD get_devn () const {return dev.devn;}
   short get_unitn () const {return dev.minor;}
   DWORD file_attributes () const {return fileattr;}