From d21edf5276c8aa21f703f926314444e8080a2dbe Mon Sep 17 00:00:00 2001
From: Corinna Vinschen <corinna@vinschen.de>
Date: Fri, 21 Jun 2013 08:14:26 +0000
Subject: [PATCH] 	* path.cc (cygwin_conv_path): Handle NULL "from" path
 gracefully. 	* path.sgml (func-cygwin-conv-path): Document returning EINVAL
 if 	"from" is NULL.

---
 winsup/cygwin/ChangeLog | 6 ++++++
 winsup/cygwin/path.cc   | 6 ++++++
 winsup/cygwin/path.sgml | 2 +-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index be9863eb3..f101a9515 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,9 @@
+2013-06-21  Corinna Vinschen  <corinna@vinschen.de>
+
+	* path.cc (cygwin_conv_path): Handle NULL "from" path gracefully.
+	* path.sgml (func-cygwin-conv-path): Document returning EINVAL if
+	"from" is NULL.
+
 2013-06-19  Christopher Faylor  <me.cygwin2013@cgf.cx>
 
 	* winf.h (av::unshift): Make __reg2.
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 9492590c3..9f4a3b5a6 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -3212,6 +3212,12 @@ cygwin_conv_path (cygwin_conv_path_t what, const void *from, void *to,
   bool relative = !!(what & CCP_RELATIVE);
   what &= CCP_CONVTYPE_MASK;
 
+  if (!from)
+    {
+      set_errno (EINVAL);
+      return -1;
+    }
+
   switch (what)
     {
     case CCP_POSIX_TO_WIN_A:
diff --git a/winsup/cygwin/path.sgml b/winsup/cygwin/path.sgml
index 26c3ea34e..79f97dff5 100644
--- a/winsup/cygwin/path.sgml
+++ b/winsup/cygwin/path.sgml
@@ -42,7 +42,7 @@ buffer size in bytes.  Otherwise, it returns 0 on success, or -1 on
 error and errno is set to one of the below values.</para>
 
 <programlisting>
-    EINVAL        what has an invalid value.
+    EINVAL        what has an invalid value or from is NULL.
     EFAULT        from or to point into nirvana.
     ENAMETOOLONG  the resulting path is longer than 32K, or, in case
                   of what == CCP_POSIX_TO_WIN_A, longer than MAX_PATH.