[PATCH] getcwd: work around mingw bug

[Eric Blake]

mingw getcwd(buf, 0) fails with ERANGE, instead of the required
EINVAL.  Since we're already replacing getcwd on mingw, the
workaround is trivial.

* lib/getcwd-lgpl.c (rpl_getcwd): Guarantee correct error.
Reported by Matthias Bolte.

Signed-off-by: Eric Blake <address@hidden>
---

It took me much less time to write this patch than to test it...

 ChangeLog         |    6 ++++++
 lib/getcwd-lgpl.c |    9 ++++++++-
 2 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 390d4e8..2e8dbe9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-05-25  Eric Blake  <address@hidden>
+
+       getcwd: work around mingw bug
+       * lib/getcwd-lgpl.c (rpl_getcwd): Guarantee correct error.
+       Reported by Matthias Bolte.
+
 2011-05-24  Paul Eggert  <address@hidden>

        test-intprops: disable -Wtype-limits diagnostics
diff --git a/lib/getcwd-lgpl.c b/lib/getcwd-lgpl.c
index 53c5562..2761422 100644
--- a/lib/getcwd-lgpl.c
+++ b/lib/getcwd-lgpl.c
@@ -45,7 +45,14 @@ rpl_getcwd (char *buf, size_t size)

   /* Handle single size operations.  */
   if (buf)
-    return getcwd (buf, size);
+    {
+      if (!size)
+        {
+          errno = EINVAL;
+          return NULL;
+        }
+      return getcwd (buf, size);
+    }

   if (size)
     {
-- 
1.7.4.4