win32: fix implementation of readlink(2)

Commit 35e32c2a71 (readlink(): do `NUL`-terminate the result) changed
how our implementation of readlink(2) handles the case where the link
is too long for the buffer.  This broke xmalloc_readlink() which
expects readlink(2) to behave as documented.  As a results symbolic
links with 80 or more characters didn't work properly.

Revert the commit.

(GitHub issue #237)

1 files changed, 2 insertions, 3 deletions

diff --git a/win32/mingw.c b/win32/mingw.c
index cd121c949..06da37040 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -1381,10 +1381,9 @@ ssize_t readlink(const char *pathname, char *buf, size_t bufsiz)
                         name[len] = 0;
                         name = normalize_ntpath(name);
                         len = wcslen(name);
-                        if (len >= bufsiz)
-                                len = bufsiz - 1;
+                        if (len > bufsiz)
+                                len = bufsiz;
                         if (WideCharToMultiByte(CP_ACP, 0, name, len, buf, bufsiz, 0, 0)) {
-                                buf[len] = '\0';
                                 return len;
                         }
                 }