win32: better handling of nested symlinks

Our realpath(3) implementation uses xmalloc_follow_symlinks() to
expand symlinks.  This detects when symlinks are too deeply nested
but didn't set errno, so anything calling realpath(3) was unable to
say what had gone wrong.  (For example, 'ls -L' or 'stat -L'.)
Set errno to ELOOP.

This then leads to the problem that Windows doesn't know about
ELOOP so reports 'Unknown error'.  Add a replacement for strerror(3)
which returns a sensible message.

Costs 96 bytes.

1 files changed, 3 insertions, 0 deletions

diff --git a/include/mingw.h b/include/mingw.h
index c4849215b..03ef89029 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -209,6 +209,9 @@ int unsetenv(const char *env);
  * string.h
  */
 char *strndup(char const *s, size_t n);
+char *mingw_strerror(int errnum);
+
+#define strerror mingw_strerror
 
 /*
  * strings.h