[PATCH] getcwd-lgpl: relax test for FreeBSD

[Eric Blake]

getcwd(NULL, 1) mallocs a larger buffer on BSD, rather than failing
with ERANGE as on glibc.  This behavior difference is not worth
coding around, as it is an uncommon use of getcwd in the first place.

* doc/posix-functions/getcwd.texi (getcwd): Document portability
issue.
* tests/test-getcwd-lgpl.c (main): Relax test.
Reported by Matthias Bolte.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog                       |    8 ++++++++
 doc/posix-functions/getcwd.texi |   10 ++++++++--
 tests/test-getcwd-lgpl.c        |   14 ++++++++++++--
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 34ccc10..a174518 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-05-13  Eric Blake  <address@hidden>
+
+       getcwd-lgpl: relax test for FreeBSD
+       * doc/posix-functions/getcwd.texi (getcwd): Document portability
+       issue.
+       * tests/test-getcwd-lgpl.c (main): Relax test.
+       Reported by Matthias Bolte.
+
 2011-05-11  Eric Blake  <address@hidden>

        test-fflush: silence compiler warning
diff --git a/doc/posix-functions/getcwd.texi b/doc/posix-functions/getcwd.texi
index 1f6dd18..a49a899 100644
--- a/doc/posix-functions/getcwd.texi
+++ b/doc/posix-functions/getcwd.texi
@@ -11,8 +11,7 @@ getcwd
 @itemize
 @item
 On glibc platforms, @code{getcwd (NULL, n)} allocates memory for the result.
-On some other platforms, this call is not allowed.  Conversely, mingw fails
-to honor non-zero @code{n}.
+On some other platforms, this call is not allowed.
 @item
 On some platforms, the prototype for @code{getcwd} uses @code{int}
 instead of @code{size_t} for the size argument:
@@ -30,4 +29,11 @@ getcwd

 Portability problems not fixed by Gnulib:
 @itemize
address@hidden
+When using @code{getcwd(NULL, nonzero)}, some platforms, such as glibc
+or cygwin, allocate exactly @code{nonzero} bytes and fail with
address@hidden if it was not big enough, while other platforms, such as
+FreeBSD or mingw, ignore the size argument and allocate whatever size
+is necessary.  If this call succeeds, an application cannot portably
+access beyond the string length of the result.
 @end itemize
diff --git a/tests/test-getcwd-lgpl.c b/tests/test-getcwd-lgpl.c
index 67ee66d..c63a9a4 100644
--- a/tests/test-getcwd-lgpl.c
+++ b/tests/test-getcwd-lgpl.c
@@ -65,12 +65,17 @@ main (int argc, char **argv)
     pwd2 = malloc (len + 2);
     for ( ; i <= len; i++)
       {
+        char *tmp;
         errno = 0;
         ASSERT (getcwd (pwd2, i) == NULL);
         ASSERT (errno == ERANGE);
+        /* Allow either glibc or BSD behavior, since POSIX allows both.  */
         errno = 0;
-        ASSERT (getcwd (NULL, i) == NULL);
-        ASSERT (errno == ERANGE);
+        tmp = getcwd (NULL, i);
+        if (tmp)
+          free (tmp);
+        else
+          ASSERT (errno == ERANGE);
       }
     ASSERT (getcwd (pwd2, len + 1) == pwd2);
     pwd2[len] = '/';
@@ -80,6 +85,11 @@ main (int argc, char **argv)
   ASSERT (strstr (pwd2, "/../") == NULL);
   ASSERT (strstr (pwd2 + 1 + (pwd2[1] == '/'), "//") == NULL);

+  /* Validate a POSIX requirement on size.  */
+  errno = 0;
+  ASSERT (getcwd(pwd2, 0) == NULL);
+  ASSERT (errno == EINVAL);
+
   free (pwd1);
   free (pwd2);

-- 
1.7.4.4