[libvirt] [PATCH] portability to non-glibc: don't use realpath(..., NULL)

[Jim Meyering]

Using realpath like that is not portable, and providing
a buffer instead of NULL is wasteful and harder to code properly.
Instead, use gnulib's canonicalize_file_name, which does
the same job portably:

>From 4afea6b59e2be6c28b45ef59a6a2f896eed44dba Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at redhat.com>
Date: Tue, 26 Jan 2010 17:13:45 +0100
Subject: [PATCH] portability to non-glibc: don't use realpath(..., NULL)

it causes a NULL-dereference on some systems like Solaris 10.
* src/node_device/node_device_linux_sysfs.c. Include <stdlib.h>.
(get_sriov_function): Use canonicalize_filen_name, not realpath.
* bootstrap (modules): Add canonicalize-lgpl.
---
 bootstrap                                 |    1 +
 src/node_device/node_device_linux_sysfs.c |    6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/bootstrap b/bootstrap
index aec5d05..cc3c6ef 100755
--- a/bootstrap
+++ b/bootstrap
@@ -68,6 +68,7 @@ modules='
 areadlink
 base64
 c-ctype
+canonicalize-lgpl
 close
 connect
 getaddrinfo
diff --git a/src/node_device/node_device_linux_sysfs.c b/src/node_device/node_device_linux_sysfs.c
index 33e658d..c1fce5d 100644
--- a/src/node_device/node_device_linux_sysfs.c
+++ b/src/node_device/node_device_linux_sysfs.c
@@ -24,6 +24,7 @@

 #include <fcntl.h>
 #include <sys/stat.h>
+#include <stdlib.h>

 #include "node_device_driver.h"
 #include "node_device_hal.h"
@@ -242,7 +243,8 @@ out:
 static int get_sriov_function(const char *device_link,
                               struct pci_config_address **bdf)
 {
-    char *device_path = NULL, *config_address = NULL;
+    char *config_address = NULL;
+    char *device_path = NULL;
     char errbuf[64];
     int ret = SRIOV_ERROR;

@@ -259,7 +261,7 @@ static int get_sriov_function(const char *device_link,

     }

-    device_path = realpath(device_link, device_path);
+    device_path = canonicalize_file_name (device_link);
     if (device_path == NULL) {
         memset(errbuf, '\0', sizeof(errbuf));
         VIR_ERROR("Failed to resolve device link '%s': '%s'", device_link,
--
1.7.0.rc0.140.gfbe7