Support GnuTLS v3.4 and later on MS-Windows

* src/gnutls.c (syms_of_gnutls) <libgnutls-version>: New DEFSYM.
* lisp/term/w32-win.el (dynamic-library-alist): Determine which
GnuTLS DLL to load according to value of libgnutls-version.

Fixes: bug#20294

Copyright-paperwork-exempt: yes

1 files changed, 10 insertions, 0 deletions

diff --git a/src/gnutls.c b/src/gnutls.c
index 35f0eb48bc1..ddd36a91e9f 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -1645,6 +1645,16 @@ DEFUN ("gnutls-available-p", Fgnutls_available_p, Sgnutls_available_p, 0, 0, 0,
 void
 syms_of_gnutls (void)
 {
+  DEFSYM (Qlibgnutls_version, "libgnutls-version");
+  Fset (Qlibgnutls_version,
+#ifdef HAVE_GNUTLS
+        make_number (GNUTLS_VERSION_MAJOR * 10000
+                     + GNUTLS_VERSION_MINOR * 100
+                     + GNUTLS_VERSION_PATCH)
+#else
+        make_number (-1)
+#endif
+        );
 #ifdef HAVE_GNUTLS
   gnutls_global_initialized = 0;