From 933e986a9207d2b61c5119e18603b44b924e7226 Mon Sep 17 00:00:00 2001
From: Laurent Bercot <ska-skaware@skarnet.org>
Date: Thu, 7 Dec 2017 15:49:02 +0000
Subject:  Finally implement sarealpath() over realpath(). Prettier
 atomic_symlink().

---
 src/libunixonacid/atomic_symlink.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

(limited to 'src/libunixonacid')

diff --git a/src/libunixonacid/atomic_symlink.c b/src/libunixonacid/atomic_symlink.c
index 660e4d3..d438263 100644
--- a/src/libunixonacid/atomic_symlink.c
+++ b/src/libunixonacid/atomic_symlink.c
@@ -4,6 +4,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
+#include <unistd.h>
 #include <skalibs/random.h>
 #include <skalibs/unix-transactional.h>
 
@@ -17,7 +18,7 @@ int atomic_symlink (char const *target, char const *name, char const *suffix)
   }
   {
     size_t namelen = strlen(name) ;
-    size_t suffixlen = suffix ? strlen(suffix) : 8 ;
+    size_t suffixlen = suffix ? strlen(suffix) : 25 ;
     char tmp[namelen + suffixlen + 2] ;
     memcpy(tmp, name, namelen) ;
     tmp[namelen] = ':' ;
@@ -25,8 +26,14 @@ int atomic_symlink (char const *target, char const *name, char const *suffix)
       memcpy(tmp + namelen + 1, suffix, suffixlen + 1) ;
     else
     {
-      random_name(tmp + namelen + 1, 8) ;
-      tmp[namelen + 9] = 0 ;
+      memcpy(tmp + namelen + 1, "atomic_symlink:", 15) ;
+      random_name(tmp + namelen + 16, 8) ;
+      tmp[namelen + 24] = 0 ;
+    }
+    {
+      int e = errno ;
+      if (unlink(tmp) < 0 && errno != ENOENT) return 0 ;
+      errno = e ;
     }
     if (symlink(target, tmp) < 0) return 0 ;
     if (rename(tmp, name) < 0)
-- 
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