Enable C99 mode for compiler. (See #3638).

This is already the default for clang (FreeBSD) so shouldn't cause any
issues.

Enabling this will increase the allowed static string length and remove
the Copyright length warning.

diff --git a/configure.ac b/configure.ac
index e0d6814a6f0e8c50f1aac9070ec7db745862e1d1..2855bd9a27c99274bb9f23858ef24bdc4f8f33e9 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -28,6 +28,7 @@ fi
 AC_MSG_RESULT($mutt_cv_prefix)
 
 AC_PROG_CC
+AC_PROG_CC_C99
 AC_SEARCH_LIBS([strerror],[cposix])
 if test "x$U" != "x"; then
   AC_MSG_ERROR(Compiler not ANSI compliant)