autoconf: don't use platform regex if it lacks REG_STARTEND
If the platform regex cannot match null bytes, we might as well
use the glibc version instead.
Cc: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Cc: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Tested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/config.mak.in b/config.mak.in
index b4e65c3..67dbd3b 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -58,6 +58,7 @@
NO_INET_PTON=@NO_INET_PTON@
NO_ICONV=@NO_ICONV@
OLD_ICONV=@OLD_ICONV@
+NO_REGEX=@NO_REGEX@
NO_DEFLATE_BOUND=@NO_DEFLATE_BOUND@
INLINE=@INLINE@
SOCKLEN_T=@SOCKLEN_T@
diff --git a/configure.ac b/configure.ac
index 5601e8b..71ac89f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -706,6 +706,27 @@
fi
AC_SUBST(NO_C99_FORMAT)
#
+# Define NO_REGEX if you have no or inferior regex support in your C library.
+AC_CACHE_CHECK([whether the platform regex can handle null bytes],
+ [ac_cv_c_excellent_regex], [
+AC_EGREP_CPP(yippeeyeswehaveit,
+ AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT
+#include <regex.h>
+],
+[#ifdef REG_STARTEND
+yippeeyeswehaveit
+#endif
+]),
+ [ac_cv_c_excellent_regex=yes],
+ [ac_cv_c_excellent_regex=yes])
+])
+if test $ac_cv_c_excellent_regex = yes; then
+ NO_REGEX=
+else
+ NO_REGEX=YesPlease
+fi
+AC_SUBST(NO_REGEX)
+#
# Define FREAD_READS_DIRECTORIES if your are on a system which succeeds
# when attempting to read from an fopen'ed directory.
AC_CACHE_CHECK([whether system succeeds to read fopen'ed directory],
