[libvirt] [PATCH] absolutePathFromBaseFile: don't leak when first arg contains no "/"

[Jim Meyering]

Not only did this function leak(p), but it would also over-allocate
(by the length of basename(base_file)), and then later, re-alloc
to compensate, so I rewrote it:

>From 1dc52930daa000b407d8a8f18588a19cf4e8b7f5 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at redhat.com>
Date: Thu, 4 Feb 2010 16:55:57 +0100
Subject: [PATCH] absolutePathFromBaseFile: don't leak when first arg contains no "/"

* src/util/storage_file.c: Include "dirname.h".
(absolutePathFromBaseFile): Rewrite not to leak, and to require
fewer allocations.
* bootstrap (modules): Add dirname-lgpl and stpncpy.
* .gnulib: Update submodule to the latest.
---
 .gnulib                 |    2 +-
 bootstrap               |    2 ++
 src/util/storage_file.c |   27 ++++++++++-----------------
 3 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/.gnulib b/.gnulib
index 146d914..9d0ad65 160000
--- a/.gnulib
+++ b/.gnulib
@@ -1 +1 @@
-Subproject commit 146d9145073e62a2096a2d6b33f75e93908fedf3
+Subproject commit 9d0ad652de159d08e5f679842f8a2a5658196361
diff --git a/bootstrap b/bootstrap
index cc3c6ef..5cc43c5 100755
--- a/bootstrap
+++ b/bootstrap
@@ -71,6 +71,7 @@ c-ctype
 canonicalize-lgpl
 close
 connect
+dirname-lgpl
 getaddrinfo
 gethostname
 getpass
@@ -93,6 +94,7 @@ send
 setsockopt
 socket
 stpcpy
+stpncpy
 strchrnul
 strndup
 strerror
diff --git a/src/util/storage_file.c b/src/util/storage_file.c
index 44057d2..8c53fba 100644
--- a/src/util/storage_file.c
+++ b/src/util/storage_file.c
@@ -1,7 +1,7 @@
 /*
  * storage_file.c: file utility functions for FS storage backend
  *
- * Copyright (C) 2007-2009 Red Hat, Inc.
+ * Copyright (C) 2007-2010 Red Hat, Inc.
  * Copyright (C) 2007-2008 Daniel P. Berrange
  *
  * This library is free software; you can redistribute it and/or
@@ -26,6 +26,7 @@

 #include <unistd.h>
 #include <fcntl.h>
+#include "dirname.h"
 #include "memory.h"
 #include "virterror_internal.h"

@@ -246,26 +247,18 @@ vmdk4GetBackingStore(virConnectPtr conn,
 static char *
 absolutePathFromBaseFile(const char *base_file, const char *path)
 {
-    size_t base_size, path_size;
-    char *res, *p;
+    char *res;
+    size_t d_len = dir_len (base_file);

-    if (*path == '/')
+    /* If path is already absolute, or if dirname(base_file) is ".",
+       just return a copy of path.  */
+    if (*path == '/' || d_len == 0)
         return strdup(path);

-    base_size = strlen(base_file) + 1;
-    path_size = strlen(path) + 1;
-    if (VIR_ALLOC_N(res, base_size - 1 + path_size) < 0)
+    if (VIR_ALLOC_N(res, d_len + 1 + strlen(path) + 1) < 0)
         return NULL;
-    memcpy(res, base_file, base_size);
-    p = strrchr(res, '/');
-    if (p != NULL)
-        p++;
-    else
-        p = res;
-    memcpy(p, path, path_size);
-    if (VIR_REALLOC_N(res, (p + path_size) - res) < 0) {
-        /* Ignore failure */
-    }
+
+    stpcpy(stpcpy(stpncpy(res, base_file, d_len), "/"), path);
     return res;
 }

--
1.7.0.rc1.199.g9253a