Pacify clang without munging C source

* configure.ac (WARN_CFLAGS): With Clang, use
-Wno-tautological-compare regardless of --enable-gcc-warnings.
(WERROR_CFLAGS): Simplify assignments, and guarantee it’s always set.
* lib/strftime.c: Copy from gnulib, reverting Clang-specific
change which I hope is no longer needed.
* src/emacs.c (main): Revert rlim_t change, as rlim_t is signed on
some older non-POSIX hosts.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/emacs.c b/src/emacs.c
index 08430de6ca7..da8df1bf1c7 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -832,7 +832,7 @@ main (int argc, char **argv)
      (https://www.cygwin.com/ml/cygwin/2015-07/msg00096.html).  */
   struct rlimit rlim;
   if (getrlimit (RLIMIT_STACK, &rlim) == 0
-      && rlim.rlim_cur <= LONG_MAX)
+      && 0 <= rlim.rlim_cur && rlim.rlim_cur <= LONG_MAX)
     {
       rlim_t lim = rlim.rlim_cur;
 
@@ -866,7 +866,7 @@ main (int argc, char **argv)
              right thing anyway.  */
           long pagesize = getpagesize ();
           newlim += pagesize - 1;
-          if (rlim.rlim_max < newlim)
+          if (0 <= rlim.rlim_max && rlim.rlim_max < newlim)
             newlim = rlim.rlim_max;
           newlim -= newlim % pagesize;