[Nano-devel] [PATCH] configure: ignore the REG_ENHANCED test when we use gnulib

[Benno Schulenberg]

From: Mike Frysinger <address@hidden>

If we're using the bundled gnulib regex module, then assume REG_ENHANCED
is not supported (since gnulib doesn't support it).

This fixes https://savannah.gnu.org/bugs/?50714.
---
 configure.ac | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index f914fa8e..a2f94c4d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -587,17 +587,26 @@ else
     fi
 fi
 
-AC_CACHE_CHECK([for enhanced regular expression flag], 
nano_cv_flag_reg_extended,
+AC_CACHE_CHECK([for enhanced regular expression flag], 
nano_cv_flag_reg_enhanced,
               [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <regex.h>]],
                                                   [[
                                                     #ifndef REG_ENHANCED
                                                     error: No REG_ENHANCED 
support!
                                                     #endif
                                                   ]])],
-                                 [nano_cv_flag_reg_extended="REG_EXTENDED | 
REG_ENHANCED"],
-                                 [nano_cv_flag_reg_extended="REG_EXTENDED"])])
+                                 [nano_cv_flag_reg_enhanced=yes],
+                                 [nano_cv_flag_reg_enhanced=no])])
+dnl The bundled gnulib regex module doesn't support REG_ENHANCED.
+if test "$ac_use_included_regex" = "yes"; then
+    nano_cv_flag_reg_enhanced="no"
+fi
+if test "$nano_cv_flag_reg_enhanced" = "yes"; then
+    nano_reg_extended="REG_EXTENDED | REG_ENHANCED"
+else
+    nano_reg_extended="REG_EXTENDED"
+fi
 
-AC_DEFINE_UNQUOTED(NANO_REG_EXTENDED, $nano_cv_flag_reg_extended,
+AC_DEFINE_UNQUOTED(NANO_REG_EXTENDED, $nano_reg_extended,
                   [Flag(s) to use to get the full range of extended regular 
expressions])
 
 # Check for word-boundary support (/< and />).
@@ -625,7 +634,7 @@ int main(void)
     size_t nmatch;
     regmatch_t pmatch;
 
-    if (regcomp(&r, "\\\\>", $nano_cv_flag_reg_extended|REG_NOSUB))
+    if (regcomp(&r, "\\\\>", $nano_reg_extended|REG_NOSUB))
        return 1;
     if (regexec(&r, "word boundary", nmatch, &pmatch, 0))
        return 1;
-- 
2.12.1