canonicalize-lgpl bug

[Eric Blake]

I noticed that glibc has applied some fixes to canonicalize.c that we were 
missing; and sure enough, was able to enhance the testsuite to trip these 
bugs.  They also applied some assert's proving that their optimization to avoid 
strcpy are safe; I left the asserts out, but copied their optimization.  OK to 
commit?

I plan on porting the testsuite changes to test-canonicalize.c, and fixing any 
fallout there as a separate commit.


From: Eric Blake <address@hidden>
Date: Thu, 10 Sep 2009 12:12:16 -0600
Subject: [PATCH] canonicalize-lgpl: reject non-directory with trailing slash

* tests/test-canonicalize-lgpl.c (main): Enhance test.
* lib/canonicalize-lgpl.c (__realpath): Synchronize with glibc.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog                      |    6 ++++++
 lib/canonicalize-lgpl.c        |   11 +++++++----
 tests/test-canonicalize-lgpl.c |   16 +++++++++++++++-
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f9d9c1b..baeaf35 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2009-09-10  Eric Blake  <address@hidden>

+       canonicalize-lgpl: reject non-directory with trailing slash
+       * tests/test-canonicalize-lgpl.c (main): Enhance test.
+       * lib/canonicalize-lgpl.c (__realpath): Synchronize with glibc.
+
+2009-09-10  Eric Blake  <address@hidden>
+
        dirname: add library-safe mdir_name
        * lib/dirname.h (mdir_name): New prototype.
        * lib/dirname.c (dir_name): Move guts...
diff --git a/lib/canonicalize-lgpl.c b/lib/canonicalize-lgpl.c
index 6b5663a..c8f313e 100644
--- a/lib/canonicalize-lgpl.c
+++ b/lib/canonicalize-lgpl.c
@@ -298,6 +298,11 @@ __realpath (const char *name, char *resolved)
                  while ((--dest)[-1] != '/');
            }
 #endif
+         else if (!S_ISDIR (st.st_mode) && *end != '\0')
+           {
+             __set_errno (ENOTDIR);
+             goto error;
+           }
        }
     }
   if (dest > rpath + 1 && dest[-1] == '/')
@@ -307,16 +312,14 @@ __realpath (const char *name, char *resolved)
   if (extra_buf)
     freea (extra_buf);

-  return resolved ? memcpy (resolved, rpath, dest - rpath + 1) : rpath;
+  return rpath;

 error:
   {
     int saved_errno = errno;
     if (extra_buf)
       freea (extra_buf);
-    if (resolved)
-      strcpy (resolved, rpath);
-    else
+    if (resolved == NULL)
       free (rpath);
     errno = saved_errno;
   }
diff --git a/tests/test-canonicalize-lgpl.c b/tests/test-canonicalize-lgpl.c
index 29b919d..87e5e46 100644
--- a/tests/test-canonicalize-lgpl.c
+++ b/tests/test-canonicalize-lgpl.c
@@ -1,5 +1,5 @@
 /* Test of execution of program termination handlers.
-   Copyright (C) 2007-2008 Free Software Foundation, Inc.
+   Copyright (C) 2007-2009 Free Software Foundation, Inc.

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -79,6 +79,20 @@ main ()
     ASSERT (result == NULL);
   }

+  /* Check that a non-directory with trailing slash yields NULL.  */
+  {
+    char *result = canonicalize_file_name ("t-can-lgpl.tmp/tra/");
+    ASSERT (result == NULL);
+    result = canonicalize_file_name ("t-can-lgpl.tmp/huk/");
+    ASSERT (result == NULL);
+  }
+
+  /* Check that a missing directory yields NULL.  */
+  {
+    char *result = canonicalize_file_name ("t-can-lgpl.tmp/ouk/..");
+    ASSERT (result == NULL);
+  }
+
   /* Check that a loop of symbolic links is detected.  */
   {
     char *result = canonicalize_file_name ("ise");
-- 
1.6.3.2