From 55246d6c1cc70e10c6f80b4880bd2cced68aa1dd Mon Sep 17 00:00:00 2001
From: William S Fulton <wsf@fultondesigns.co.uk>
Date: Mon, 3 Nov 2008 14:03:21 +0000
Subject: [PATCH] apply debian/patches/05_nfs_fix.diff

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@10906 626c5289-ae23-0410-ae9c-e8d60b6d4f22
---
 CCache/ccache.1 |  6 ------
 CCache/util.c   | 19 ++++++++++++++++++-
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/CCache/ccache.1 b/CCache/ccache.1
index 9d1cbcdf9..daf3323f9 100644
--- a/CCache/ccache.1
+++ b/CCache/ccache.1
@@ -381,12 +381,6 @@ ccache can handle a much wider ranger of compiler options
 .IP o 
 ccache avoids a double call to cpp on a cache miss
 .PP 
-.SH "BUGS" 
-.PP 
-When the cache is stored on an NFS filesystem, the filesystem must be
-exported with the \fBno_subtree_check\fP option to make renames between
-directories reliable\&.
-.PP 
 .SH "CREDITS" 
 .PP 
 Thanks to the following people for their contributions to ccache
diff --git a/CCache/util.c b/CCache/util.c
index a6b88997c..70d7ea7d4 100644
--- a/CCache/util.c
+++ b/CCache/util.c
@@ -58,9 +58,26 @@ void copy_fd(int fd_in, int fd_out)
 	}
 }
 
+static int safe_rename(const char* oldpath, const char* newpath)
+{
+    /* safe_rename is for creating entries in the cache.
+
+       Works like rename(), but it never overwrites an existing
+       cache entry. This avoids corruption on NFS. */
+    int status = link( oldpath, newpath );
+    if( status == 0 || errno == EEXIST )
+    {
+	return unlink( oldpath );
+    }
+    else
+    {
+	return -1;
+    }
+}
+ 
 /* move a file using rename */
 int move_file(const char *src, const char *dest) {
-	return rename(src, dest);
+	return safe_rename(src, dest);
 }
 
 /* copy a file - used when hard links don't work