renameatu: Fix test failure on MSVC.

* lib/at-func2.c (at_func2): Fail with ENOENT if file1 or file2 is the
empty string.

2 files changed, 13 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index ea2e86a0da..d6209efafc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2019-07-03  Bruno Haible  <bruno@clisp.org>
 
+	renameatu: Fix test failure on MSVC.
+	* lib/at-func2.c (at_func2): Fail with ENOENT if file1 or file2 is the
+	empty string.
+
+2019-07-03  Bruno Haible  <bruno@clisp.org>
+
 	mbrtowc: Fix invalid use of mbtowc() on MSVC.
 	* lib/mbrtowc.c: Include glthread/lock.h.
 	(mbtowc_lock): New variable.
diff --git a/lib/at-func2.c b/lib/at-func2.c
index eaa256cb1e..bb8792f6e1 100644
--- a/lib/at-func2.c
+++ b/lib/at-func2.c
@@ -176,6 +176,13 @@ at_func2 (int fd1, char const *file1,
         return func (file1, file2); /* Reduced to case 5.  */
     }
 
+  /* Catch invalid arguments before changing directories.  */
+  if (file1[0] == '\0' || file2[0] == '\0')
+    {
+      errno = ENOENT;
+      return -1;
+    }
+
   /* Cases 3, 7, 12, 13, 15a, 15b remain.  With all reductions in
      place, it is time to start changing directories.  */