From 8bea6ce4920cab0c065bcc6ae1eb0b26fc582ebe Mon Sep 17 00:00:00 2001
From: Janne Blomqvist <jb@gcc.gnu.org>
Date: Sun, 29 May 2011 16:17:17 +0300
Subject: [PATCH] PR 49214 fd_gets should return NULL if nothing was read

From-SVN: r174395
---
 libgfortran/ChangeLog           | 5 +++++
 libgfortran/runtime/backtrace.c | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index 1d08da8c3b9..f0e3078e8b3 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,8 @@
+2011-05-29  Janne Blomqvist  <jb@gcc.gnu.org>
+
+	PR libfortran/49214
+	* runtime/backtrace.c (fd_gets): Return NULL if nothing was read.
+
 2011-05-29  Janne Blomqvist  <jb@gcc.gnu.org>
 
 	PR libfortran/19155
diff --git a/libgfortran/runtime/backtrace.c b/libgfortran/runtime/backtrace.c
index dff4466aa56..943332ab615 100644
--- a/libgfortran/runtime/backtrace.c
+++ b/libgfortran/runtime/backtrace.c
@@ -95,6 +95,8 @@ fd_gets (char *s, int size, int fd)
       else
 	{
 	  s[i] = '\0';
+	  if (i == 0)
+	    return NULL;
 	  break;
 	}
     }