Port --enable-gcc-warnings to clang.

* configure.ac (nw): Remove obsolescent warnings.
These aren't needed for clang, or for gcc for that matter.
(emacs_cv_clang): New var, which tests for clang.
Omit warnings that clang is too picky about.
(GLIB_DISABLE_DEPRECATION_WARNINGS): Define this;
needed for Ubuntu 13.04 + clang + --enable-gcc-warnings.
* lib-src/etags.c: Omit unnecessary forward decls.
(print_version, print_help): Declare _Noreturn.
* lib-src/pop.c (socket_connection) [HAVE_GETADDRINFO]: Simplify.
* src/bytecode.c (exec_byte_code):
* src/regex.c:
Redo diagnostic pragmas to pacify clang, too.
* src/dbusbind.c (xd_retrieve_arg): Do not use uninitialized variable.
* src/editfns.c (Fencode_time):
* src/fileio.c (file_accessible_directory_p):
* src/font.c (font_unparse_xlfd):
Use '&"string"[index]' instead of '"string" + (index)'.
* src/undo.c (user_error): Remove; unused.

1 files changed, 15 insertions, 21 deletions

diff --git a/lib-src/pop.c b/lib-src/pop.c
index 1f3f82baa6..a269144c91 100644
--- a/lib-src/pop.c
+++ b/lib-src/pop.c
@@ -1075,28 +1075,22 @@ socket_connection (char *host, int flags)
 	}
     } while (ret != 0);
 
-  if (ret == 0)
-    {
-      it = res;
-      while (it)
-        {
-          if (it->ai_addrlen == sizeof (addr))
-            {
-              struct sockaddr_in *in_a = (struct sockaddr_in *) it->ai_addr;
-              addr.sin_addr = in_a->sin_addr;
-              if (! connect (sock, (struct sockaddr *) &addr, sizeof (addr)))
-                break;
-            }
-          it = it->ai_next;
-        }
-      connect_ok = it != NULL;
-      if (connect_ok)
-        {
-          realhost = alloca (strlen (it->ai_canonname) + 1);
-          strcpy (realhost, it->ai_canonname);
-        }
-      freeaddrinfo (res);
+  for (it = res; it; it = it->ai_next)
+    if (it->ai_addrlen == sizeof addr)
+      {
+	struct sockaddr_in *in_a = (struct sockaddr_in *) it->ai_addr;
+	addr.sin_addr = in_a->sin_addr;
+	if (! connect (sock, (struct sockaddr *) &addr, sizeof addr))
+	  break;
+      }
+  connect_ok = it != NULL;
+  if (connect_ok)
+    {
+      realhost = alloca (strlen (it->ai_canonname) + 1);
+      strcpy (realhost, it->ai_canonname);
     }
+  freeaddrinfo (res);
+
 #else /* !HAVE_GETADDRINFO */
   do
     {